VRpursuits: Interaction in Virtual Reality Using Smooth Pursuit Eye Movements

Gaze-based interaction using smooth pursuit eye movements (Pursuits) is attractive given that it is intuitive and overcomes the Midas touch problem. At the same time, eye tracking is becoming increasingly popular for VR applications. While Pursuits was shown to be effective in several interaction contexts, it was never explored in-depth for VR before. In a user study (N=26), we investigated how parameters that are specific to VR settings influence the performance of Pursuits. For example, we found that Pursuits is robust against different sizes of virtual 3D targets. However performance improves when the trajectory size (e.g., radius) is larger, particularly if the user is walking while interacting. While walking, selecting moving targets via Pursuits is generally feasible albeit less accurate than when stationary. Finally, we discuss the implications of these findings and the potential of smooth pursuits for interaction in VR by demonstrating two sample use cases: 1) gaze-based authentication in VR, and 2) a space meteors shooting game

Behavior Analysis of Human Locomotion in Real World and Virtual Reality for Manufacturing Industry

Agethen P, Subramanian Sekar V, Gaisbauer F, Pfeiffer T, Otto M, Rukzio E. Behavior Analysis of Human Locomotion in Real World and Virtual Reality for Manufacturing Industry. ACM Transactions on Applied Perception (TAP). 2018;15(3): 20.With the rise of immersive visualization techniques, many domains within the manufacturing industry are increasingly validating production processes in virtual reality (VR). The validity of the results gathered in such simulations, however, is widely unknown - in particular with regard to human locomotion behavior. To bridge this gap, this paper presents an experiment, analyzing the behavioral disparity between human locomotion being performed without any equipment and in immersive virtual reality while wearing a head-mounted display (HMD). The presented study (n = 30) is split up in three sections and covers linear walking, non-linear walking and obstacle avoidance. Special care has been given to design the experiment so that findings are generally valid and can be applied to a wide range of domains beyond the manufacturing industry. The findings provide novel insights into the effect of immersive virtual reality on specific gait parameters. In total, a comprehensive sample of 18.09 km is analyzed. The results reveal that the HMD had a medium effect (up to 13%) on walking velocity, on non-linear walking towards an oriented target and on clearance distance. The overall-differences are modeled using multiple regression models, thus allowing the general usage within various domains. Summarizing, it can be concluded that VR can be used to analyze and plan human locomotion, however, specific details may have to be adjusted in order to transfer findings to the real world

Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition

Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie

Letter from Rauscher & Thies

Letter concerning bank and office fixtures

Xjava: Exploiting parallelism with objectoriented stream programming

Abstract. This paper presents the XJava compiler for parallel programs. It exploits parallelism based on an object-oriented stream programming paradigm. XJava extends Java with new parallel constructs that do not expose programmers to low-level details of parallel programming on shared memory machines. Tasks define composable parallel activities, and new operators allow an easier expression of parallel patterns, such as pipelines, divide and conquer, or master/worker. We also present an automatic run-time mechanism that extends our previous work to automatically map tasks and parallel statements to threads. We conducted several case studies with an open source desktop search application and a suite of benchmark programs. The results show that XJava reduces the opportunities to introduce synchronization errors. Compared to threaded Java, the amount of code could be reduced by up to 39%. The run-time mechanism helped reduce effort for performance tuning and achieved speedups up to 31.5 on an eight core machine.