Journal:Informatica
Volume 13, Issue 2 (2002), pp. 163–176
Abstract
This paper is concerned with design, implementation and verification of persistent purely functional data structures which are motivated by the representation of natural numbers using positional number systems. A new implementation of random-access list based on redundant segmented binary numbers is described. It uses 4 digits and an invariant which guarantees constant worst-case bounds for cons, head, and tail list operations as well as logarithmic time for lookup and update. The relationship of random-access list with positional number system is formalized and benefits of this analogy are demonstrated.
Journal:Informatica
Volume 10, Issue 1 (1999): Special Issue on Programming Theory, Information System Engineering, Software Engineering, and Artificial Intelligence, pp. 71–88
Abstract
One of the key issues in information systems is to provide a fast and reliable access to data. This is true for conventional databases and information systems as well as for spatial or multimedia ones. Main tools for such aim are indices, among others. Search and reasoning operations using indices and structured data require a specific support on logical and physical level. A years of research have resulted in a great variety of multidimensional data structures and indices (access methods also). This paper overviews recent trends in the area of multidimensional, spatial, temporal indices and data structures, discusses their principles and implementation issues. The special emphasis is given to research, multimedia and spatial information systems.
Journal:Informatica
Volume 2, Issue 1 (1991), pp. 100–116
Abstract
The hierarchical principle of video-information analysis (progressive detalisation) is one from the set of principles which are implemented in the living vision system. The reflection of this principle in the techniques of the representation of a shape of the region, occupied by binary image, allows us to find a solution of two tasks simultaneously: data compression and data structure, which suits for geometric transformations of the image. This report includes operations which are performed on the hierarchical list of rectangles. The latter is built up by using intermediate pyramidal representation.