Topological predicates are an important element of database systems that allow manipulation of spatial data. Based on the necessity for such systems to handle uncertainty, we introduce a general mechanism that identifies vague topological predicates. This definition forms part of a formal data model referred to as VASA (Vague Spatial Algebra), in which the data types vague regions, vague lines,...

This paper investigates the implications for contracting problems with adverse selection of assuming a more general information structure than usual. The paper applies a choice theoretic framework introduced in Olszewski (2007) and Ahn (2008) a special case of the vague environments in Vierø (2009a) to a canonical principal-agent model with hidden information. The vague environment reflects tha...

Many geographical applications deal with objects in space that cannot be adequately described by determinate, crisp spatial concepts because of their intrinsically indeterminate and vague nature. Geographical information systems and spatial database systems are currently unable to cope with this kind of data. To support the efficient representation, querying, and manipulation of vague spatial d...

Naturally occurring phenomena in space often (if not always) cannot be precisely defined because of the intrinsic uncertainty of their features. The location of animal refuges might not be precisely known, and the path of rivers might be uncertain due to water volume fluctuations and changing land characteristics. The extension of lakes can also change and thus have uncertain areas. All these a...

Vague predicates such as heap, tall, bald, near to, nicer than, etc. are characterized by their Sorites susceptibility and the existence of borderline cases. In attempting to develop a general theory, diverse vague predicates are often analyzed in rather broad natural language settings. Because this has proven to be rather difficult, the phenomenon of vagueness is studied here in a narrower and...

let $l$ be a completely regular frame and $mathcal{r}l$ be the ‎ring of continuous real-valued functions on $l$‎. ‎we show that the‎ ‎lattice $zid(mathcal{r}l)$ of $z$-ideals of $mathcal{r}l$ is a‎ ‎normal coherent yosida frame‎, ‎which extends the corresponding $c(x)$‎ ‎result of mart'{i}nez and zenk‎. ‎this we do by exhibiting‎ ‎$zid(mathcal{r}l)$ as a quotient of $rad(mathcal{r}l)$‎, ‎the‎ ‎...