We present a formalization of how specifications are constructed using superposition and composition in the Ocsid specification language. The formalization covers stepwise refinement using superposition and composition of independent refinements. Independent views of a refinement hierarchy (subclassing and operation refinement) are reconciled in composition in a formally well founded way. The f...

Telecommunication systems must have a high degree of availability, that is, a high probability of correct and timely provision of requested services. To achieve this, correctness of software for such systems should be ensured. Application of formal methods helps increase confidence in building correct software. However, to be used in practice, formal methods should be well integrated into exist...

Today’s complex online applications often require the interaction of multiple (web) services that belong to potentially different business entities. Interoperability is a core element of such an environment, yet not a straightforward one due to the lack of common data semantics. The problem is often approached by means of standardization procedures in a top-down manner with limited adoption in ...

Service orientation has become a buzzword in research and practice during the last years. Enterprises consider investing in service-oriented architectures to increase the reuse of their existing software and to decrease development time and costs. On the one hand, standardization committees have advanced to define many layers of technical standards that are to become the technical backbone of a...

Recent studies have suggested the techniques of aspect-oriented and feature-oriented programming be combined to overcome their individual shortcomings. While previous work mainly argues on the basis of conceptual considerations and micro examples, in this paper, we evaluate the key ideas quantitatively by means of a non-trivial case study, a product line for overlay networks. Specifically, we p...

Global SLS-resolution is a well-known procedural semantics for top-down computation of queries under the well-founded model. It inherits from SLDNF-resolution the linearity property of derivations, which makes it easy and efficient to implement using a simple stack-based memory structure. However, like SLDNF-resolution it suffers from the problem of infinite loops and redundant computations. To...

Pedestrians are important participants in urban traffic environments, and thus act as an interesting category of objects for autonomous cars. Automatic pedestrian detection is an essential task for protecting pedestrians from collision. In this thesis, we investigate and develop novel approaches by interpreting spatial and temporal characteristics of pedestrians, in three different aspects: sha...

Global SLS-resolution and SLG-resolution are two representative mechanisms for top-down evaluation of the well-founded semantics of general logic programs. Global SLS-resolution is linear but suffers from infinite loops and redundant computations. In contrast, SLG-resolution resolves infinite loops and redundant computations by means of tabling, but it is not linear. The distinctive advantage o...

Research has revealed the entanglement of e-government strategy and information infrastructure and that the control of infrastructures often remains an illusion as actual development and implementation is challenged by a constant drift. However, guidelines for public sector CIOs how to deal with these challenges remain scarce: Are governments well advised using architectures and other conceptua...

the aim of this study was to investigate the role of coach-oriented organization and team performance in the mental health staff general directorate of youth and sport of ardabil. descriptive and correlational methodology has been applied to the target and the field was done in this study population all staff general directorate of youth and sport was ardabil province in the number of them 85 p...