Franz Lehner

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ion and partitioning. The majority of projects developed prototypes ranging from simple mock-ups to operational prototypes. A third of the RE teams developed OO models. Most projects verified and validated requirements with multiple stakeholders. More than half the projects performed peer reviews or walk-throughs to verify or validate requirements.(More)
This paper outlines the components of a mobile education system and lists selected examples of universities employing m−education. Several possible approaches in designing and installing such a system are discussed. The main focus is on the project WELCOME (Wireless E−Learning and Communication Environ− ment) at the University of Regensburg. We argue that(More)
A combinatorial formula is derived which expresses free cumulants in terms of classical comulants. As a corollary, we give a combinatorial interpretation of free cumulants of classical distributions, notably Gaussian and Poisson distributions. The latter count connected pairings and connected partitions respectively. The proof relies on Möbius inversion on(More)
This paper deals with Organisational Memory Systems (OMS) which are seen as a new kind of information systems. OMS result from the application of advanced database and network technologies to support Organisational Memory concepts and approaches. First, the notion of OMS, the origin of these systems, their theoretical background and the evolution of data(More)
Mobile services available on mobile devices such as mobile phones and Personal Digital Assistants are a suitable instrument for spontaneous, ad-hoc access to information travellers need while being on the move. The supply of mobile services with specific relevance to the traveller is already well developed: Mobile Services allow to book last-minute trips,(More)
User comments are the most popular but also extremely controversial form of communication on YouTube. Their public image is very poor; users generally expect that most comments will be of little value or even in thoroughly bad taste. Nevertheless, heaps of comments continue to be posted every day. We propose an explanation for this contradiction in user(More)
In this paper, an intuitive authoring system and player for interactive non-linear video called SIVA Suite is presented for demonstration. Such videos are enriched by additional content. Possible forms of additional content are plaintext, richtext, images and videos. Interactivity is implemented based upon selection buttons which allow the user to follow(More)