Artur Czumaj, Christian Sohler, Heinz Nixdorf
The min-sum k-clustering problem is to partition a metric space (P,d) into k clusters C1,...,Ck ⊆ P such that �k � i=1 d(p,q) is minimized. We show the first efficient construction of a coreset...
Design of Partially Reconfigurable Systems: From Abstract Modeling to Practical Realization (2008)
Florian Dittmann, Heinz Nixdorf
Abstract — The possibility of partial reconfiguration of FPGAs during run-time can be used to implement systems that adapt their execution area over time. Such resource optimization is especially...
SAN Optimal Multi Parameter Access Scheme (2008)
Christian Schindelhauer, Gunnar Schomaker, Heinz Nixdorf
Abstract. Storage area networks consist of a set of n data servers that handle a collection of m documents. Such SANs can minimize the access time to documents by distributing each document among the...
ABSTRACT Time-Critical Collision Detection Using an Average-Case Approach (2008)
We present a novel, generic framework and algorithm for hierarchical collision detection, which allows an application to balance speed and quality of the collision detection. We pursue an...
Frank Götz, Bernd Eßmann, Heinz Nixdorf, Thorsten Hampel
Mobile cooperation systems are in focus of current CSCW/L research. Most approaches try to build special clients for mobile devices or new architectures for distributed cooperation systems. The same...
We present k-Flipper, a graph transformation algorithm that transforms regular undirected graphs. Given a path of k + 2 edges it interchanges the end vertices of the path. By definition this...
Artur Czumaj, Christian Sohler, Heinz Nixdorf
We present a novel analysis of a random sampling approach for four clustering problems in metric spaces: k-median, k-means, min-sum k-clustering, and balanced k-median. For all these problems we...
A FRAMEWORK FOR DISTRIBUTED OBJECTS IN PEER-TO-PEER COOPERATION ENVIRONMENTS (2008)
Bernd Eßmann, Thorsten Hampel, Heinz Nixdorf
Abstract: Mobile forms of cooperative knowledge organization need system architectures that also allow spontaneous (ad hoc) networking and collaboration structures. An essential requirement here,...
Artur Czumaj, Christian Sohler, Heinz Nixdorf
In this paper we present a sublinear time (1 + ɛ)-approximation randomized algorithm to estimate the weight of the minimum spanning tree of an n-point metric space. The running time of the algorithm...
Tolerance of Radial Basis Functions against Stuck-At-Faults (2008)
Ralf Eickhoff, Ulrich Ruckert, Heinz Nixdorf
Neural networks are intended to be used in future nanoelectronic systems since neural architectures seem to be robust against malfunctioning elements and noise in their weights. In this paper we...
Estimating the Weight of Metric Minimum Spanning (2008)
Artur Czumaj, Christian Sohler, Heinz Nixdorf
In this paper we present a sublinear time (1 +#)-approximation randomized algorithm to estimate the weight of the minimum spanning tree of an n-point metric space. The running time of the algorithm...
Miros/law Kuty/lowski z (2007)
Martin Dietzfelbinger, Heinz Nixdorf, Fachbereich Mathematik-informatik, Rudiger Reischuk
y Partially supported by DFG grant ME 872/1-4 and by DFG-Forschergruppe "Effiziente Nutzung paralleler
Klaus Brockmann And, Klaus Brockmann, Wilhelm Dangelmaier, Heinz Nixdorf
The term flexible flow line (FFL) denotes a generalization of the standard flow shop where at least one stage comprises more than one machine. We present a scheduling algorithm for the FFL which...
C-LAB: Cooperative Computing & Communication Laboratory, (2007)
Heinz Nixdorf, Wolfram Hardt, Siemens Nixdorf, Informationssysteme Ag
State Machine Models Giuseppe Del Castillo Heinz Nixdorf Institut Department of Mathematics & Computer Science University of Paderborn Furstenallee 11, 33102 Paderborn, Germany Wolfram Hardt...
Object Recognition in Image Sequences with Cellular Neural Networks (2007)
Mariofanna Milanova, Ulrich Büker, Heinz Nixdorf
In this paper, the application of CNN associative memories for 3D object recognition is presented. The main idea is to analyse the optical flow in an image sequence of an object. Several features of...
A scalable Processor Array for Selforganizing Feature Maps (2007)
S. Rüping, U. Rückert, Heinz Nixdorf
Selforganizing Feature Maps (SOFMs) can be applied for data analysis, controlling problems and pattern matching. In many cases the requirements of a system using these maps are high performance and...
ABSTRACT Time-Critical Collision Detection Using an Average-Case Approach (2007)
We present a novel, generic framework and algorithm for hierarchical collision detection, which allows an application to balance speed and quality of the collision detection. We pursue an...
Randomized Point Sampling for Output-Sensitive Rendering of Complex Dynamic Scenes (2007)
Michael W, Michael Wand, Matthias Fischer, Matthias Fischer, ...
We present a new output-sensitive rendering algorithm, the randomized z-buffer algorithm. It renders an image of a three dimensional scene of triangular primitives by reconstruction from a random...
wolfk @ uni-paderborn.de Summary (2007)
Bengt Mueck, Matthias Fischer, Wilhelm Dangelmaier, Wolfram Klemisch, Heinz Nixdorf, Heinz Nixdorf
Visualising is a method used to help experiencing and understanding causal cohesions in simulation processes. For this purpose, tools for visualising are already implemented in prevalent simulation...
C-LAB: Cooperative Computing & Communication Laboratory, (2007)
Heinz Nixdorf, Wolfram Hardt, Siemens Nixdorf, Informationssysteme Ag
High level design decisions as HW/SW-partitioning and instrumenting of building blocks can be supported efficiently by detailed analysis of dynamic instruction usage. In many cases the instruction...
Partitioned Neighborhood Spanners of Minimal Outdegree (2007)
Heinz Nixdorf, Matthias Fischer, Tamas Lukovszki, Martin Ziegler
A geometric spanner with vertex set P ae IR D is a sparse approximation of the complete Euclidean graph determined by P. We introduce the notion of partitioned neighborhood graphs (PNGs), unifying...
Ecient Parallel Simulation of Pulse-Coded Neural Networks (PCNN) (2007)
R. Preis, K. Salzwedel, G. Hartmann, C. Wol, Heinz Nixdorf
Abstract Neural networks are the common model for brain style data processing. Therefore, the algorithms are inherently parallel and a parallel implementation of neural network simulations seems to...
Improved Bounds for Online Multi-Path Routing in Faulty Mesh Networks (2006)
Stefan Rührup, Heinz Nixdorf, Christian Schindelhauer
We consider the problem of route discovery in a mesh network with faulty nodes. The number and the positions of the faulty nodes are unknown. It is known that a flooding strategy like expanding ring...
Competitive Time and Traffic Analysis of Position-based Routing using a Cell Structure (2005)
Stefan Rührup, Christian Schindelhauer, Heinz Nixdorf
We present a strategy for organizing the communication in wireless ad hoc networks based on a cell structure. We use the unit disk graph model and assume positioning capabilities for all nodes. The...
Performance Analysis of the Hierarchical Layer Graph for Wireless Networks (2005)
Stefan Rührup, Christian Schindelhauer, Klaus Volbert, Heinz Nixdorf
Recently, a promising network topology for wireless networks, called the Hierarchical Layer Graph (HL graph), has been introduced and analyzed by Meyer auf der Heide et al. 2004. This graph can be...
Probability distributions for channel utilisation (2005)
Christian Schindelhauer, Kerstin Voß, Heinz Nixdorf
Abstract. Sensor nets have many undisputed fields of application. A paradigm of communication is the use of one control channel in the MAC layer. We challenge this paradigm for nodes with very...
weak spanners, and power spanners for wireless networks (2004)
Christian Schindelhauer, Klaus Volbert, Martin Ziegler, Heinz Nixdorf
Abstract. For c ∈ R, ac-spanner is a subgraph of a complete Euclidean graph satisfying that between any two vertices there exists a path of weighted length at most c times their geometric distance....
A network component architecture for collaboration in mobile settings (2004)
Bernd Eßmann, Thorsten Hampel, Heinz Nixdorf
Abstract: Today Computer Supported Cooperative Work (CSCW) is used in broad areas of human cooperation. With the propagation of radio-based communication and ad hoc networking it may enter new areas...
Time-Critical Collision Detection Using an Average-Case Approach (2003)
Jan Klein, Gabriel Zachmann, Heinz Nixdorf
We present a novel, generic framework and algorithm for hierarchical collision detection, which allows an application to balance speed and quality of the collision detection.
Worst case mobility in ad hoc networks (2003)
Christian Schindelhauer, Tamas Lukovszki, Stefan Rührup, Klaus Volbert, Heinz Nixdorf
We investigate distributed algorithms for mobile ad hoc networks for moving radio stations with adjustable transmission power in a worst case scenario. We consider two models to find a reasonable...
Worst case mobility in ad hoc networks (2003)
Christian Schindelhauer, Tamas Lukovszki, Stefan Rührupý, Klaus Volbert, Heinz Nixdorf
We investigate distributed algorithms for mobile ad hoc networks for moving radio stations with adjustable transmission power in a worst case scenario. We consider two models to find a reasonable...
Artur Czumaj, Christian Sohler, Heinz Nixdorf
In this paper we present a sublinear time (1+ɛ)-approximation randomized algorithm to estimate the weight of the minimum spanning tree of an n-point metric space. The running time of the algorithm...
Human computer interaction and cooperative learning in mobile environments (2003)
Bernd Eßmann, Thorsten Hampel, Heinz Nixdorf
Starting out on network supported cooperative learning environments for classical learning scenarios, this article discusses their possible enhancements with respect to new standards of mobile...
Minimizing congestion in general networks (2002)
A principle task in parallel and distributed systems is to reduce the communication load in the interconnection network, as this is usually the major bottleneck for the performance of distributed...
Distributed Maintenance of Resource Efficient Wireless Network Topologies (2002)
Matthias Grünewald, Tamás Lukovszki, Christian Schindelhauer, Klaus Volbert, Heinz Nixdorf
Abstract. Multiple hop routing in mobile ad hoc networks can minimize energy consumption and increase data throughput. Yet, the problem of radio interferences remains. However if the routes are...
Randomized point sampling for output-sensitive rendering of complex dynamic scenes (2000)
Michael Wand, Matthias Fischer, Heinz Nixdorf
We present a new output-sensitive rendering algorithm, the randomized z-buffer algorithm. It renders an image of a three dimensional scene of triangular primitives by reconstruction from a random...
Testing Convex Position (2000)
Artur Czumaj, Martin Ziegler, Heinz Nixdorf, Christian Sohler
In this paper we present a property tester for the convex position property of points sets.
Partitioned Neighborhood Spanners of Minimal Outdegree (1999)
Heinz Nixdorf, Matthias Fischer, Tamas Lukovszki, Martin Ziegler
A geometric spanner with vertex set P ae IR D is a sparse approximation of the complete Euclidean graph determined by P. We introduce the notion of partitioned neighborhood graphs (PNGs), unifying...
Partitioned Neighborhood Spanners of Minimal Outdegree (1999)
Matthias Fischer Tamas, Heinz Nixdorf, Matthias Fischer, Tamas Lukovszki, Martin Ziegler
A geometric spanner with vertex set P ae IR D is a sparse approximation of the complete Euclidean graph determined by P. We introduce the notion of partitioned neighborhood graphs (PNGs), unifying...
SDL Formal Semantics Definition (1999)
Uwe Glässer, Heinz Nixdorf, Reinhard Gotzhein, Andreas Prinz
Grammar 12 3.1 Abstract Syntax Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.2 AST of the Example Specification . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 ASM...
Hybrid Object Models: Combining Symbolic and Subsymbolic Object Recognition Strategies (1998)
In this paper, we describe a hybrid object recognition system. The integration of biologically motivated subsymbolic image recognition and of symbolic reasoning and control mechanisms shows a rapid...
Cellular Neural Networks In Active Vision System (1998)
Ulrich Büker, Heinz Nixdorf, Mariofanna Milanova
In this paper, the application of CNN associative memories for 3D object recognition is presented. The main idea is to analyse the optical flow in an image sequence of an object. Several features of...
Cellular Neural Networks For Complex Object Recognition (1998)
Mariofanna Milanova, Ulrich Büker, Heinz Nixdorf
In this paper, the application of CNN associative memories for 3D object recognition is presented. The main idea is to analyse the optical flow in an image sequence of an object. Several features of...
Allocating Independent Tasks (1997)
One of the most important problems in the efficient use of parallel systems is to distribute the workload evenly among the servers. An instance of this problem is the problem of independent...
Efficient Oblivious Parallel Sorting on the MasPar MP-1 (1997)
Klaus Brockmann, Heinz Nixdorf, Rolf Wanka
We address the problem of sorting a large number N of keys on a MasPar MP-1 parallel SIMD machine of moderate size P where the processing elements (PEs) are interconnected as a toroidal mesh and have...
Rule-Based Modelling in Fuzzy Simulation (1995)
Eyke Hüllermeier, Heinz Nixdorf
We argue that continuity is a basic principle in commonsense physical reasoning and propose differential inclusions as an appropriate basis for dealing with uncertain dynamics in semi-quantitative...
Simple, Efficient Shared Memory Simulations (Extended Abstract) (1993)
Martin Dietzfelbinger, Heinz Nixdorf
We present three shared memory simulations on distributed memory machines (DMMs), which use universal hashing to distribute the shared memory cells over the memory modules of the DMM. We measure...