Figure 1.
Schematic drawing of the Digital Sign System (DSS).
Figure 2.
Segmentation of a Digital Tag’s image from its background.
Left: a digital tag on a wall. Right: the IR image of the same tag demonstrating the segmentation advantage offered by the retro-reflective effect and unique patterns within the tag design.
Figure 3.
Example of a look-up table used in the Tag Browsing Mode.
The table contains hexadecimal sign numbers and corresponding text messages.
Figure 4.
Operating range of the Tag Reader (green).
The boundaries of the green region show the maximum and minimum distances for successful reading of the tags as a function of the angle between the tag reader and the normal to the tag.
Figure 5.
Accuracy (the percentage of successful tag-recognition events out of a total of 38 opportunities during four traversals of a corridor) in the Tag Browsing Experiment: Medians (red lines), the 25% and 75% quartile limits (blue boxes), and the minimum and maximum values (whiskers) are shown for three groups of subjects.
Figure 6.
Building Navigator Explore Mode.
A subject’s location and north-facing direction are indicated by the red triangle in the floor plan. See the text for a description of the functionality of the Explore mode.
Figure 7.
The bar plots show trial-by-trial times-to-completion for individual subjects in the three groups when they used the tag reader (lower panels) or did not use the tag reader (upper panels). Yellow bars designate outliers. Two box plots at the right show the distributions of the times-to-completion for the three groups of subjects in terms of the median times (red lines), 25% and 75% quartile limits (blue boxes), the maximum and minimum values (whiskers), and outliers (red crosses) for the three groups. Upper and lower dash lines, when present, mark the preset range limits if any outliers are outside the limits. Separate box plots show times for testing with and without the tag reader. A third box plot shows the within-subjects difference in times-to-completion with and without the tag reader.
Figure 8.
Building Navigator Route Finding Mode.
A subject, located at the red triangle, wishes to travel to the target location marked by the purple star. Waypoints are indicated by circles. Note that “East-West” and “North-South” in the verbal descriptions refer to corridors. See the text for a description of the functionality of the route-finding mode.
Figure 9.
The bar plots show trial-by-trial times for individual subjects in the three groups when they used the tag reader (lower panels) or did not use the tag reader (upper panels). Yellow bars designate outliers. Two box plots at the right show the distributions of the times-to-completion for the three groups of subjects in terms of the median times (red lines), 25% and 75% quartile limits (blue boxes), the maximum and minimum values (whiskers), and outliers (red crosses) for the three groups. Upper and lower dash lines, when present, mark the preset range limits if any outliers are outside the limits. Separate box plots show times for testing with and without the tag reader. A third box plot shows the within-subjects difference in times-to-completion with and without the tag reader.