Feasibility and validity of a low-cost racing simulator in driving assessment after stroke

There is a myriad of methodologies to assess driving performance after a stroke. These include psychometric tests, driving simulation, questionnaires, and/or road tests. Research-based driving simulators have emerged as a safe, convenient way to assess driving performance after a stroke. Such traditional research simulators are useful in recreating street traffic scenarios, but are often expensive, with limited physics models and graphics rendering. In contrast, racing simulators developed for motorsport professionals and enthusiasts offer high levels of realism, run on consumer-grade hardware, and can provide rich telemetric data. However, most offer limited simulation of traffic scenarios. This pilot study compares the feasibility of research simulation and racing simulation in a sample with minor stroke. We determine that the racing simulator is tolerated well in subjects with a minor stroke. There were correlations between research and racing simulator outcomes with psychometric tests associated with driving performance, such as the Trails Making Test Part A, Snellgrove Maze Task, and the Motricity Index. We found correlations between measures of driving speed on a complex research simulator scenario and racing simulator lap time and maximum tires off track. Finally, we present two models, using outcomes from either the research or racing simulator, predicting road test failure as linked to a previously published fitness-to-drive calculator that uses psychometric screening

Multiresolution Document Analysis with Wavelets

The n-gram analysis technique breaks up a text documentinto several n-character long unique grams, and produces a vector whose components are the counts of these grams. Atypical corpus contains hundreds of thousands of such grams. Wavelet compression reduces the dimension of the n-gram vectors, and speeds up document query operations. Documentvectors with their dimensions reduced to four components is readily represented in a three dimensional volume

Multiresolution Document Analysis with Wavelets

The n-gram analysis technique breaks up a text document into several n-character long unique grams, and produces a vector whose components are the counts of these grams. A typical corpus contains hundreds of thousands of such grams. Wavelet compression reduces the dimension of the n-gram vectors, and speeds up document query operations. Document vectors with their dimensions reduced to four components is readily represented in a three dimensional volume. Keywords: information retrieval, n-gram analysis, wavelets, multiresolution analysis, volume visualization, glyph-based volume rendering. 1 Introduction Text documents are represented as multi-dimensional vectors in n-gram document analysis technique. The document is broken down into unique grams. The frequencies of these grams are used as the components of the vector representing that document. A gram is a consecutive sequence of n characters that appear in the document. The vector representation allows us to use the cosine of the..

Two-handed interactive stereoscopic visualization

This paper describes a minimally immersive interactive system for visualization of multivariate volumetric data. The system, SFA, uses glyph-based volume rendering which does not suffer the initial costs of isosurface rendering or voxel-based volume rendering, while offering the capability of viewing the entire volume. Glyph rendering also allows the simultaneous display of multiple data values per volume location. Two-handed interaction using three-space magnetic trackers and stereoscopic viewing are combined to produce a minimally immersive volumetric visualization system that enhances the user's three-dimensional perception of the data. We describe the usefulness of this system for visualizing volumetric scalar and vector data. SFA allows the three-dimensional volumetric visualization, manipulation, navigation, and analysis of multivariate, time-varying volumetric data, increasing the quantity and clarity of the information conveyed from the visualization system.