In this paper, we proposed an automatic spherical maze generation framework. Traditional mazes are generated on two or three dimensional spaces, with regular grids as walls and paths. Instead of pure two or three dimensional mazes, we automatically generate maze on the surface of a sphere, which provides a unique and fresh maze solving experience. Because regular grids on spherical surface will...

In this paper an analytic formulation of the statics and the instantaneous kinematics of robot manipulators based on the Grassmann-Cayley algebra is presented. The notions of twist, wrench, twist space and wrench space are mathematically represented by the concept of extensors of this algebra and the reciprocity relation between twist and wrench spaces of partially constrained rigid bodies is r...

Time of creation is one of the predominant (often implicit) clustering strategies found not only in Data Warehouse systems: line items are created together with their corresponding order, objects are created together with their subparts and so on. The newly created data is then appended to the existing data. We present a new join algorithm, called DiagJoin, which exploits time-of-creation clust...

Today’s mobile devices feature many resources, sensors and data, which make it possible for them to adapt to their environment. However, they would have a lot more resources at hand, and thus could better adapt to their context, if they used their communication capabilities to share their resources with others near them. In this paper we propose the concept of ad-hoc smart spaces, which enables...

In this article we give a partial answer to an important open problem in descriptive set theory, the Decomposability Conjecture on Borel functions from an analytic subset of a Polish space into a separable metrizable space. Our techniques employ deep results from effective descriptive set theory and recursion theory. In fact it is essential to prove that several prominent results in recursion t...

In modern database applications the similarity of complex objects is examined by performing distance-based queries (e.g. nearest neighbour search) on data of high dimensionality. Most multidimensional indexing methods have failed to efficiently support these queries in arbitrary high-dimensional datasets (due to the dimensionality curse). Similarity join queries and K closest pairs queries are ...