The aspect of reusing hypermedia course materials must be already regarded in the earlier modelling phases of the development, in order to enable such an implementation. In this work we present a concept for designing and implementing hypermedia courses with special consideration of reusing same course materials in several courses. The automatic generation of courses is supported through deriva...

Let k = k be a quadratic number field with discriminant ∆. For n ≥ 0, we define fields k inductively by taking k as the compositum of all unramified quadratic extensions of k that are central over k. Then k(∞) = ⋃∞ n=0 k (n,2) is the 2-class field tower of k. In the following, we call k the n central 2-step. The structure of the Galois group Gal (k/k) of the first central 2-step is determined b...

In this article we give a survey of the current practice and state-of-theart of recommender services in scientific digital libraries. With the notable exception of amazon.com and CiteSeer which do not qualify as proper scientific libraries our survey revealed that in scientific libraries recommender services are still not in wide use – despite the considerable benefits they offer for students a...

Scientific digital library systems are a very promising application area for value-added expert advice services. Such systems could significantly reduce the search and evaluation costs of information products for students and scientists. This holds for pure digital libraries as well as for traditional scientific libraries with online public access catalogs (OPAC). In this contribution we first ...

In this paper we present an algorithm for narrowing the constraint y = e x. The algorithm has been designed to be fast by using only IEEE multiplication. The main diiculty is to design algorithms which soundly, rapidly, and precisely compute upper and lower bounds on e x and ln(y). We prove that our algorithms are correct and produce upper and lower bounds which diier by at most 2 ULP. Experime...

INTRODUCTION The requirements of minimally invasive surgery (MIS) show a significant similarity to the conditions of teleoperation tasks in nuclear plants and other inaccessible working areas. The software package KISMET (Kinematic Simulation, Monitoring and Off-Line Programming Environment for Telerobotics) is under development at Kernforschungszentrum Karlsruhe (KfK), Germany, since 1986, for...

Surgical training systems based on virtual reality (VR) and simulation techniques for tissue deformation may represent a more cost-e!ective and e$cient alternative to traditional training methods. Additionally, VR is a technology that can teach surgeons new procedures and can determine their level of competence before they operate on patients. At Forschungszentrum Karlsruhe (FZK), a virtual rea...

Background Food allergy to egg is commonly diagnosed in childhood with good prognosis. Egg white is considered as the main culprit with major 4 identified allergens (Gal d 1 to Gal d 4). Egg yolk (with two identified allergens Gal d 5 and Gal d 6 in the livetin fraction) retained less attention and its clinical involvement remains unclear. This study revisits sensitization to both egg fractions...