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Many scientific disciplines with an intrinsically high degree of multimedia content can be found among the life-sciences. Among the various faculties of medicine, especially dermatology is renowned for extensive use of clinical images in lectures and in textbooks. Training the “diagnostic eye” is an important part of the medical education. Furthermore, large collections of images, traditionally organized...
In this article, we discuss combinatorial auctions, an interesting inter-disciplinary research field in Computer Science and Economics. In particular, we will (a) describe a set of real-world cases, (b) how to solve the associated computational problems, and (c) discuss the impact of the probability distributions chosen for benchmarking.
Software components realising the graphical user interface (GUI) of a highly interactive system or the user interface of a Web application form an essential part of the entire implementation and significantly affect the effectiveness and maintainability of the software system. In this paper, we propose a software engineering based approach for the development of complex Web-based user interfaces (Web-UIs)...
Since 1980, I have taught almost every year an elementary course on algorithms and data structures, first for the third and later for the second semester. The first perfor-mances - in PL/I times - were heavily based on [5]. Later the course became increasingly independent of any single textbook, and now makes use of a large number of sources, including, of course, the author’s proper experiences....
The pagination problem of complex documents is in placing text and floating objects on pages in such a way that each object appears close to, but not before, its text reference. Current electronic formatting systems do not offer the pagination quality provided by human experts in traditional bookprinting. One reason is that a good placement of text and floating objects cannot be achieved in a single...
Extended context-free grammars are context-free grammars in which the right-hand sides of productions are allowed to be any regular language rather than being restricted to only finite languages. We present a novel view on topdown predictive parser construction for extended context-free grammars that is based on the rewriting of partial syntax trees. This work is motivated by our development of ECFG,...
Time-evolving data structures deal with the temporal development of object sets describing in turn some kind of real-world phenomena. In the bitemporal case also objects having counterparts with an own predefined temporal component can be modelled. In this paper, we consider a subset of the problems usually covered by this context, having many real applications in which certain real-time constraints...
We present fast algorithms for merging and sorting of data on a multiprocessor system connected through a Partitioned Optical Passive Stars (POPS) network. In a POPS(d, g) network there are n = dg processors and they are divided into g groups of d processors each. There is an optical passive star (OPS) coupler between every pair of groups. Each OPS coupler can receive an optical signal from any one...
Navigation systems assist almost any kind of motion in the physical world including sailing, flying, hiking, driving and cycling. On the other hand, traces supplied by global positioning systems (GPS) can track actual time and absolute coordinates of the moving objects. Consequently, this paper addresses efficient algorithms and data structures for the route planning problem based on GPS data;...
In this paper we present different exact and heuristic optimization methods for scheduling planes which want to land (and start) at an airport - the Aircraft Sequencing Problem (ASP). We compare two known integer programming formulations with four new exact and heuristic solution methods regarding quality, speed and flexibility.
The hierarchical radiosity algorithm is an efficient approach to simulation of light with the goal of photo-realistic image rendering. Hanrahan et. al. describe the initialization and the refinement of links between the scene’s patches based upon a user-specified error parameter ε . They state that the number of links is linear in the number of elements if ε is assumed to be a constant. We present...
Neural Trees are introduced. These descendants of decision trees are used to represent (approximations to) arbitrary continuous functions. They support efficient evaluation and the application of arithmetic operations, differentiation and definite integration.
This paper is dedicated to Thomas Ottmann on the occasion of his 60th birthday.We discuss the design of several Java applets that visualize how the Voronoi diagram of n points continuously changes as individual points are moved across the plane, or as the underlying distance function is changed. Moreover, we report on some experiences made in using these applets in teaching and research. The applets...
Virtual University is a buzzword. However, in spite of manifold activities e-learning, that is the usage of multimedia and network technology to benefit or profit the students, will not inevitably be adopted in the university. On the contrary, these technologies have to be strongly pushed and the characteristics and specific culture of traditional universities have to be taken into account. Various...
In the automotive and aerospace industry, millions of technical documents are generated during the development of complex engineering products. Particularly, the universal application of Computer Aided Design (CAD) from the very first design to the final documentation created the need for transactional, concurrent, reliable, and secure data management. The huge underlying CAD databases, occupying...
Testing containment of conjunctive queries is the question whether for any such queries Q1,Q2, for any database instance D, the set of answers of one query is contained in the set of answers of the other. In this paper, we first introduce into the general approach for testing for the case, when both queries do not contain negation. Based on these techniques we discuss the question for the case of...
In this paper it is explained what Knowledge Management (KM) is and why it will play an important role in the future. This implies that KM is indeed more than just the sophisticated use of information systems or distributed databases for complex tasks. With the introduction of the Maurer-Tochtermann model for KM and the description of the basic elements of new techniques, it can be demonstrated quite...
When I was asked to contribute to a volume dedicated to Thomas Ottmann’s sixtieth birthday, I immediately agreed. I have known Thomas for more than 25 years, I like him, and I admire his work and his abilities as a cyclist. Of course, when it came to start writing, I started to have second thoughts.What should I write about? I could have taken one of my recent papers. But that seemed inappropriate;...
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