@article{579, abstract = {{A left-to-right maximum in a sequence of n numbers s_1, …, s_n is a number that is strictly larger than all preceding numbers. In this article we present a smoothed analysis of the number of left-to-right maxima in the presence of additive random noise. We show that for every sequence of n numbers s_i ∈ [0,1] that are perturbed by uniform noise from the interval [-ε,ε], the expected number of left-to-right maxima is Θ(&sqrt;n/ε + log n) for ε>1/n. For Gaussian noise with standard deviation σ we obtain a bound of O((log3/2 n)/σ + log n).We apply our results to the analysis of the smoothed height of binary search trees and the smoothed number of comparisons in the quicksort algorithm and prove bounds of Θ(&sqrt;n/ε + log n) and Θ(n/ε+1&sqrt;n/ε + n log n), respectively, for uniform random noise from the interval [-ε,ε]. Our results can also be applied to bound the smoothed number of points on a convex hull of points in the two-dimensional plane and to smoothed motion complexity, a concept we describe in this article. We bound how often one needs to update a data structure storing the smallest axis-aligned box enclosing a set of points moving in d-dimensional space.}}, author = {{Damerow, Valentina and Manthey, Bodo and Meyer auf der Heide, Friedhelm and Räcke, Harald and Scheideler, Christian and Sohler, Christian and Tantau, Till}}, journal = {{Transactions on Algorithms}}, number = {{3}}, pages = {{30}}, publisher = {{ACM}}, title = {{{Smoothed analysis of left-to-right maxima with applications}}}, doi = {{10.1145/2229163.2229174}}, year = {{2012}}, } @misc{582, author = {{Strothmann, Thim Frederik}}, publisher = {{Universität Paderborn}}, title = {{{Self-Optimizing Binary Search Trees - A Game Theoretic Approach}}}, year = {{2012}}, } @misc{594, author = {{Klerx, Timo}}, publisher = {{Universität Paderborn}}, title = {{{Online Parameteroptimierung in P2P-Netzwerken mit Hilfe von Neuronalen Netzen}}}, year = {{2012}}, } @misc{600, author = {{Feldkord, Björn}}, publisher = {{Universität Paderborn}}, title = {{{Lokale Swaps und überholte Informationen in Basic Network Creation Games}}}, year = {{2012}}, } @phdthesis{601, abstract = {{Wir betrachten eine Gruppe von mobilen, autonomen Robotern in einem ebenen Gel{\"a}nde. Es gibt keine zentrale Steuerung und die Roboter m{\"u}ssen sich selbst koordinieren. Zentrale Herausforderung dabei ist, dass jeder Roboter nur seine unmittelbare Nachbarschaft sieht und auch nur mit Robotern in seiner unmittelbaren Nachbarschaft kommunizieren kann. Daraus ergeben sich viele algorithmische Fragestellungen. In dieser Arbeit wird untersucht, unter welchen Voraussetzungen die Roboter sich auf einem Punkt versammeln bzw. eine Linie zwischen zwei festen Stationen bilden k{\"o}nnen. Daf{\"u}r werden mehrere Roboter-Strategien in verschiedenen Bewegungsmodellen vorgestellt. Diese Strategien werden auf ihre Effizienz hin untersucht. Es werden obere und untere Schranken f{\"u}r die ben{\"o}tigte Anzahl Runden und die Bewegungsdistanz gezeigt. In einigen F{\"a}llen wird außerdem die ben{\"o}tigte Bewegungsdistanz mit derjenigen Bewegungsdistanz verglichen, die eine optimale globale Strategie auf der gleichen Instanz ben{\"o}tigen w{\"u}rde. So werden kompetititve Faktoren hergeleitet.}}, author = {{Kempkes, Barbara}}, isbn = {{978-3-942647-21-2}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Local strategies for robot formation problems}}}, volume = {{302}}, year = {{2012}}, } @article{6055, author = {{Mehler, Alexander and Lücking, Andy and Menke, Peter}}, issn = {{0893-6080}}, journal = {{Neural Networks}}, pages = {{159--164}}, publisher = {{Elsevier BV}}, title = {{{Assessing cognitive alignment in different types of dialog by means of a network model}}}, doi = {{10.1016/j.neunet.2012.02.013}}, volume = {{32}}, year = {{2012}}, } @inbook{6057, author = {{Menke, Peter}}, booktitle = {{Handbook of Technical Communication}}, isbn = {{978-3-11-018834-9}}, pages = {{285–314}}, publisher = {{de Gruyter}}, title = {{{Evaluation of Technical Communication}}}, volume = {{8}}, year = {{2012}}, } @misc{618, author = {{Kurras, Sven}}, publisher = {{Universität Paderborn}}, title = {{{Distributed Sampling of Regular Graphs}}}, year = {{2012}}, } @inproceedings{619, abstract = {{Dynamics in networks is caused by a variety of reasons, like nodes moving in 2D (or 3D) in multihop cellphone networks, joins and leaves in peer-to-peer networks, evolution in social networks, and many others. In order to understand such kinds of dynamics, and to design distributed algorithms that behave well under dynamics, many ways to model dynamics are introduced and analyzed w.r.t. correctness and eciency of distributed algorithms. In [16], Kuhn, Lynch, and Oshman have introduced a very general, worst case type model of dynamics: The edge set of the network may change arbitrarily from step to step, the only restriction is that it is connected at all times and the set of nodes does not change. An extended model demands that a xed connected subnetwork is maintained over each time interval of length T (T-interval dynamics). They have presented, among others, algorithms for counting the number of nodes under such general models of dynamics.In this paper, we generalize their models and algorithms by adding random edge faults, i.e., we consider fault-prone dynamic networks: We assume that an edge currently existing may fail to transmit data with some probability p. We rst observe that strong counting, i.e., each node knows the correct count and stops, is not possible in a model with random edge faults. Our main two positive results are feasibility and runtime bounds for weak counting, i.e., stopping is no longer required (but still a correct count in each node), and for strong counting with an upper bound, i.e., an upper bound N on n is known to all nodes.}}, author = {{Brandes, Philipp and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 4th Workshop on Theoretical Aspects of Dynamic Distributed Systems (TADDS)}}, pages = {{9--14}}, title = {{{Distributed Computing in Fault-Prone Dynamic Networks}}}, doi = {{10.1145/2414815.2414818}}, year = {{2012}}, } @inproceedings{625, abstract = {{This paper initiates the study of self-adjusting distributed data structures for networks. In particular, we present SplayNets: a binary search tree based network that is self-adjusting to routing request.We derive entropy bounds on the amortized routing cost and show that our splaying algorithm has some interesting properties.}}, author = {{Schmid, Stefan and Avin, Chen and Scheideler, Christian and Häupler, Bernhard and Lotker, Zvi}}, booktitle = {{Proceedings of the 26th International Symposium on Distributed Computing (DISC)}}, pages = {{439--440}}, title = {{{Brief Announcement: SplayNets - Towards Self-Adjusting Distributed Data Structures}}}, doi = {{10.1007/978-3-642-33651-5_47}}, year = {{2012}}, } @inproceedings{626, abstract = {{The design of ecient search structures for peer-to-peer systems has attracted a lot of attention in recent years. In this announcement we address the problem of nding the predecessor in a key set and present an ecient data structure called hashed Predecessor Patricia trie. Our hashed Predecessor Patricia trie supports PredecessorSearch(x) and Insert(x) and Delete(x) in O(log log u) hash table accesses when u is the size of the universe of the keys. That is the costs only depend on u and not the size of the data structure. One feature of our approach is that it only uses the lookup interface of the hash table and therefore hash table accesses may be realized by any distributed hash table (DHT).}}, author = {{Kniesburges, Sebastian and Scheideler, Christian}}, booktitle = {{Proceedings of the 26th International Symposium on Distributed Computing (DISC)}}, pages = {{435--436}}, title = {{{Brief Announcement: Hashed Predecessor Patricia Trie - A Data Structure for Efficient Predecessor Queries in Peer-to-Peer Systems}}}, doi = {{10.1007/978-3-642-33651-5_45}}, year = {{2012}}, } @inproceedings{628, abstract = {{Network creation games model the creation and usage costs of networks formed by a set of selfish peers.Each peer has the ability to change the network in a limited way, e.g., by creating or deleting incident links.In doing so, a peer can reduce its individual communication cost.Typically, these costs are modeled by the maximum or average distance in the network.We introduce a generalized version of the basic network creation game (BNCG).In the BNCG (by Alon et al., SPAA 2010), each peer may replace one of its incident links by a link to an arbitrary peer.This is done in a selfish way in order to minimize either the maximum or average distance to all other peers.That is, each peer works towards a network structure that allows himself to communicate efficiently with all other peers.However, participants of large networks are seldom interested in all peers.Rather, they want to communicate efficiently with a small subset only.Our model incorporates these (communication) interests explicitly.Given peers with interests and a communication network forming a tree, we prove several results on the structure and quality of equilibria in our model.We focus on the MAX-version, i.e., each node tries to minimize the maximum distance to nodes it is interested in, and give an upper bound of O(\sqrt(n)) for the private costs in an equilibrium of n peers.Moreover, we give an equilibrium for a circular interest graph where a node has private cost Omega(\sqrt(n)), showing that our bound is tight.This example can be extended such that we get a tight bound of Theta(\sqrt(n)) for the price of anarchy.For the case of general networks we show the price of anarchy to be Theta(n).Additionally, we prove an interesting connection between a maximum independent set in the interest graph and the private costs of the peers.}}, author = {{Cord-Landwehr, Andreas and Huellmann (married name: Eikel), Martina and Kling, Peter and Setzer, Alexander}}, booktitle = {{Proceedings of the 5th International Symposium on Algorithmic Game Theory (SAGT)}}, pages = {{72----83}}, title = {{{Basic Network Creation Games with Communication Interests}}}, doi = {{10.1007/978-3-642-33996-7_7}}, year = {{2012}}, } @inproceedings{632, abstract = {{Given an integer h, a graph G = (V;E) with arbitrary positive edge capacities and k pairs of vertices (s1; t1); (s2; t2); : : : ; (sk; tk), called terminals, an h-route cut is a set F µ E of edges such that after the removal of the edges in F no pair si ¡ ti is connected by h edge-disjoint paths (i.e., the connectivity of every si ¡ ti pair is at most h ¡ 1 in (V;E n F)). The h-route cut is a natural generalization of the classical cut problem for multicommodity °ows (take h = 1). The main result of this paper is an O(h722h log2 k)-approximation algorithm for the minimum h-route cut problem in the case that s1 = s2 = ¢ ¢ ¢ = sk, called the single source case. As a corollary of it we obtain an approximate duality theorem for multiroute multicom-modity °ows and cuts with a single source. This partially answers an open question posted in several previous papers dealing with cuts for multicommodity multiroute problems.}}, author = {{Kolman, Petr and Scheideler, Christian}}, booktitle = {{Proceedings of the 23th ACM SIAM Symposium on Discrete Algorithms (SODA)}}, pages = {{800--810}}, title = {{{Approximate Duality of Multicommodity Multiroute Flows and Cuts: Single Source Case}}}, doi = {{10.1137/1.9781611973099.64}}, year = {{2012}}, } @inproceedings{636, abstract = {{We consider an online facility location problem where clients arrive over time and their demands have to be served by opening facilities and assigning the clients to opened facilities. When opening a facility we must choose one of K different lease types to use. A lease type k has a certain lease length lk. Opening a facility i using lease type k causes a cost of f k i and ensures that i is open for the next lk time steps. In addition to costs for opening facilities, we have to take connection costs ci j into account when assigning a client j to facility i. We develop and analyze the first online algorithm for this problem that has a time-independent competitive factor.This variant of the online facility location problem was introduced by Nagarajan and Williamson [7] and is strongly related to both the online facility problem by Meyerson [5] and the parking permit problem by Meyerson [6]. Nagarajan and Williamson gave a 3-approximation algorithm for the offline problem and an O(Klogn)-competitive algorithm for the online variant. Here, n denotes the total number of clients arriving over time. We extend their result by removing the dependency on n (and thereby on the time). In general, our algorithm is O(lmax log(lmax))-competitive. Here lmax denotes the maximum lease length. Moreover, we prove that it is O(log2(lmax))-competitive for many “natural” cases. Such cases include, for example, situations where the number of clients arriving in each time step does not vary too much, or is non-increasing, or is polynomially bounded in lmax.}}, author = {{Meyer auf der Heide, Friedhelm and Pietrzyk, Peter and Kling, Peter}}, booktitle = {{Proceedings of the 19th International Colloquium on Structural Information & Communication Complexity (SIROCCO)}}, pages = {{61--72}}, title = {{{An Algorithm for Facility Leasing}}}, doi = {{10.1007/978-3-642-31104-8_6}}, year = {{2012}}, } @misc{638, author = {{Eidens, Fabian}}, publisher = {{Universität Paderborn}}, title = {{{Adaptive Verbindungsstrategien in dynamischen Suchnetzwerken}}}, year = {{2012}}, } @inproceedings{640, abstract = {{Small-world networks have received significant attention because of their potential as models for the interaction networks of complex systems. Specifically, neither random networks nor regular lattices seem to be an adequate framework within which to study real-world complex systems such as chemical-reaction networks, neural networks, food webs, social networks, scientific-collaboration networks, and computer networks. Small-world networks provide some desired properties like an expected polylogarithmic distance between two processes in the network, which allows routing in polylogarithmic hops by simple greedy routing, and robustness against attacks or failures. By these properties, small-world networks are possible solutions for large overlay networks comparable to structured overlay networks like CAN, Pastry, Chord, which also provide polylogarithmic routing, but due to their uniform structure, structured overlay networks are more vulnerable to attacks or failures. In this paper we bring together a randomized process converging to a small-world network and a self-stabilization process so that a small-world network is formed out of any weakly connected initial state. To the best of our knowledge this is the first distributed self-stabilization process for building a small-world network.}}, author = {{Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian}}, booktitle = {{Proceedings of the 26th IEEE International Parallel and Distributed Processing Symposium (IPDPS)}}, pages = {{1261----1271}}, title = {{{A Self-Stabilization Process for Small-World Networks}}}, doi = {{10.1109/IPDPS.2012.115}}, year = {{2012}}, } @misc{641, author = {{Schluessler, Jonathan}}, publisher = {{Universität Paderborn}}, title = {{{A Forensic Framework for Automatic Information Retrieval in Distributed Systems}}}, year = {{2012}}, } @article{16242, author = {{Elsässer, Brigitta and Dohmeier-Fischer, Silvia and Fels, Gregor}}, issn = {{1610-2940}}, journal = {{Journal of Molecular Modeling}}, pages = {{3169--3179}}, title = {{{Theoretical investigation of the enzymatic phosphoryl transfer of β-phosphoglucomutase: revisiting both steps of the catalytic cycle}}}, doi = {{10.1007/s00894-011-1344-5}}, year = {{2012}}, } @inbook{31795, author = {{Böker, Ines}}, booktitle = {{Die vergnügte Gesellschaft? Ernsthafte Perspektiven auf modernes Amüsement}}, editor = {{Heinlein, Michael and Seßler, Katharina }}, pages = {{265--274}}, publisher = {{transcript }}, title = {{{„Wenn dich die Freude frisst oder freust du dich – dann fress ich dich. Zur Lesbarkeit einer Spaßanthropophagie in der Kritik der Spaßgesellschaft“}}}, year = {{2012}}, } @inbook{31832, author = {{Ballweg, Sandra}}, booktitle = {{Methoden empirischer Fremdsprachenforschung im Prozess – ein Blick hinter die Kulissen aktueller Forschungsprojekte (MatDaF 88)}}, editor = {{Cerri, Chiara and Jentges, Sabine and Stork, Antje}}, pages = {{21--35}}, publisher = {{Universitätsverlag}}, title = {{{Portfolioarbeit im fremdsprachlichen Schreibunterricht. Annäherung an das Forschungsfeld}}}, year = {{2012}}, }