Theoretical study of peculiarities of unstable longitudinal shear crack growth in sub-Rayleigh and supershear regimes

In the paper we present the results of the theoretical study of some fundamental aspects of mode II crack propagation in conventional sub-Rayleigh regime and transition to intersonic regime. It is shown that development of a sub-Rayleigh shear crack is determined in many respects by elastic vortex traveling ahead of the crack tip at a shear wave velocity. Formation of such a vortex helps to better understand the well-known phenomenon of acceleration of a shear crack towards the longitudinal wave velocity. Simulation results have shown that due to self-similarity of shear crack propagation the conditions of sub-Rayleigh to intersonic transition depend on dimensionless material and crack parameters. Two key dimensionless parameters are proposed

Authoring of automatic data preparation and scene enrichment for maritime virtual reality applications

When realizing virtual reality scenarios for the maritime sector a key challenge is dealing with the huge amount of data. Adding interactive behaviour for providing a rich interactive experience manually requires a lot of time and effort. Additionally, even though shipyards today often use PDM or PLM systems to manage and aggregate the data, the export to a visualisation format is not without problems and often needs some post procession to take place. We present a framework, that combines the capabilities of processing large amounts of data for preparing virtual reality scenarios and enriching it with dynamic aspects like interactive door opening capabilities. An authoring interface allows orchestrating the data preparation chain by non-expert users to realise individual scenarios easily

Specifying the Representation of Non-geometric Information in 3D Virtual Environments

In 3D virtual environments (3DVE), we need to know what an object looks like (i.e. geometric information) and what the object is, what are its properties and characteristics and how it relates to other objects (i.e. non-geometric information). Several interactive presentation techniques have been devised to incorporate non-geometric information into 3DVEs. The relevance of a technique depends on the context. Therefore, the choice of an appropriate representation technique cannot be done once for all and must be adapted to the context. In this paper, we first present a preliminary classification of representation techniques for non-geometric information in 3DVE. Then we propose a formalism, based on description logics, to describe the usability of a technique in a given context. We show how these descriptions can be processed to select appropriate techniques when automatically or semi-automatically generating a 3DVE

X-O arch menu: Combining precise positioning with efficient menu selection on touch devices

Support for precise positioning is cruical for many touch applications, and an efficient way to select the action at that point is very desirable in many cases as well. We draw upon existing work in the area of touch accuracy and touch menus to contribute the X-O Arch Menu. Our menu seamlessly combines precise positioning and fast, hierarcial menu selection. Furthermore, we introduce a novel optimization to pie menus that allows usage in limited screen space. The menu is fully implemented; we have created a touch-enabled version of a commercially available application using it. Copyrigh

Ein Mikrosystem zur kontaktlosen Temperaturmessung

Das integrierte Sensorsystem IRTS1 und der dazu passende Controllerbaustein TC10 dienen zum Aufbau eines hybriden Mikrosystems zur kontaktlosen Temperaturmessung auf der Basis von IR-Sensoren. Merkmale wie die direkte Ansteuerung eines LC-Displays, der integrierte AD-Wandler und eine Anzahl nützlicher Schnittstellen (seriell, parallel) verringern den Aufwand an zusätzlich notwendiger Logik entscheidend und gestatten den Einsatz in kompakten low-cost-Systemen