Recognizing the context of use is important in making mobile devices simple to use. The device and the underlying mobile service can provide a personalized user interface that adapts to the usage situation. The device can infer parts of the context of the user from features extracted from on-board measurements of acceleration, noise level, luminosity, humidity, etc. In this paper we consider co...

This paper extends European research on generating cartographic base maps at multiple scales from a single detailed database. Similar to the European work, we emphasize reference maps. In contrast to the Europeans’ focus on data generalization, we emphasize changes to the map display, including symbol design or symbol modification. We also work from databases compiled at multiple resolutions ra...

Proportional symbol maps are frequently used to represent numerical data. Commonly used symbols are squares or circles that are area-proportional to the numerical values. Proportional-symbol mapping is included in most geographic information systems (GIS) and is frequently used in digital atlases or Web mapping engines. Graduated symbols are simple for the map author to generate and easy for th...

A receiver is developed for MAP symbol detection of a burst (i.e., nite-length) CPM signal received in additive white Gaussian noise. This minimum probability of symbol error receiver requires the entire burst of data and involves the use of both forward and backward recursions. Performance results are provided comparing the MAP symbol detector to the more commonly used ML sequence detector (i....

We study the actions of the Lie algebra nsl(2,C) of SL(2,C) and the associated Casimir operator on the space of pseudodifferential operators of n variables. We describe the effect of the Casimir operator on a pseudodifferential operator in connection with the symbol map and construct an nsl(2,C)-invariant lifting of the symbol map.

This paper presents a maximum a posteriori (MAP) equalizer for bandlimited signals on frequency selective fading channels. A key contribution is the way in which the state-space of the MAP trellis is expanded for the purpose of joint channel estimation and equalization. The fading channel is estimated by coupling minimum mean square error techniques with the expanded MAP trellis. The symbol-by-...

In this article we propose a calculus of qualitative geographic coordinates which allows reasoning about cardinal directions on grid-based reference systems in maps. Grids in maps can be considered as absolute reference systems. The analysis reveals that the basic information coded in these reference systems is ordering information. Therefore, no metric information is required. We show that it ...