Informatica

Purpose: Few studies in the literature address the success of enterprise Information Systems (IS) projects, namely focusing on how success is influenced by project management practices. This research studied the impact of ISO 21500/PMBOK processes on the success of IS projects, aiming to contribute to a better understanding of management practices importance in the context of this type of projects. Design/methodology/approach: An international survey was used to collect data, which was analysed using descriptive and inferential statistics. Findings: The results show higher levels of success than usually reported in the literature. Furthermore, this research shows that overall success is strongly influenced by ISO/PMBOK project management processes, thus reinforcing the relevance of competent project management to improve the results of IS projects. Originality: Focusing on the specific case of IS projects, this study shows that higher levels of success are achieved by organizations with higher project management maturity.

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.

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.