@inproceedings{477, abstract = {{We consider the k-token dissemination problem, where k initially arbitrarily distributed tokens have to be disseminated to all nodes in a dynamic network (as introduced by Kuhn et al., STOC 2010). In contrast to general dynamic networks, our dynamic networks are unit disk graphs, i.e., nodes are embedded into the Euclidean plane and two nodes are connected if and only if their distance is at most R. Our worst-case adversary is allowed to move the nodes on the plane, but the maximum velocity v_max of each node is limited and the graph must be connected in each round. For this model, we provide almost tight lower and upper bounds for k-token dissemination if nodes are restricted to send only one token per round. It turns out that the maximum velocity v_max is a meaningful parameter to characterize dynamics in our model.}}, author = {{Abshoff, Sebastian and Benter, Markus and Cord-Landwehr, Andreas and Malatyali, Manuel and Meyer auf der Heide, Friedhelm}}, booktitle = {{Algorithms for Sensor Systems - 9th International Symposium on Algorithms and Experiments for Sensor Systems, Wireless Networks and Distributed Robotics, {ALGOSENSORS} 2013, Sophia Antipolis, France, September 5-6, 2013, Revised Selected Papers}}, pages = {{22--34}}, title = {{{Token Dissemination in Geometric Dynamic Networks}}}, doi = {{10.1007/978-3-642-45346-5_3}}, year = {{2013}}, } @article{480, abstract = {{Although of considerable practical importance, the separate impact of individual and collective reputation on firm performance (e.g. product prices) has not yet been convincingly demonstrated. We use a sample of some 70 different wineries offering more than 1,300 different Riesling wines from the Mosel valley to isolate the returns to individual reputation (measured by expert ratings in a highly respected wine guide) from the returns to collective reputation (measured by membership in two different professional associations where members are assumed to monitor each other very closely). We find that both effects are statistically significant and economically relevant with the latter being more important in quantitative terms than the former.}}, author = {{Frick, Bernd and Simmons, Robert}}, journal = {{Journal of Business Economics}}, number = {{2}}, pages = {{101--119}}, publisher = {{Springer}}, title = {{{The Impact of Individual and Collective Reputation on Wine Prices: Empirical Evidence from the Mosel Valley}}}, doi = {{10.1007/s11573-013-0652-x}}, volume = {{83}}, year = {{2013}}, } @inproceedings{481, abstract = {{Cloud computing offers high availability, dynamic scalability, and elasticity requiring only very little administration. However, this service comes with financial costs. Peer-to-peer systems, in contrast, operate at very low costs but cannot match the quality of service of the cloud. This paper focuses on the case study of Wikipedia and presents an approach to reduce the operational costs of hosting similar websites in the cloud by using a practical peer-to-peer approach. The visitors of the site are joining a Chord overlay, which acts as first cache for article lookups. Simulation results show, that up to 72% of the article lookups in Wikipedia could be answered by other visitors instead of using the cloud.}}, author = {{Graffi, Kalman and Bremer, Lars}}, booktitle = {{Proceedings of the International Conference on Communications (ICC'13)}}, pages = {{3444 -- 3449 }}, title = {{{Symbiotic Coupling of P2P and Cloud Systems: The Wikipedia Case}}}, doi = {{10.1109/ICC.2013.6655082}}, year = {{2013}}, } @misc{490, author = {{Wallaschek, Felix}}, publisher = {{Universität Paderborn}}, title = {{{Routing in heterogenen OpenFlow Netzwerken}}}, year = {{2013}}, } @misc{492, author = {{Robbert, Christoph}}, publisher = {{Universität Paderborn}}, title = {{{Ressource-Optimized Deployment of Multi-Tier Applications - The Data Rate-Constrained Case}}}, year = {{2013}}, } @misc{493, author = {{Terentjew, Artjom}}, publisher = {{Universität Paderborn}}, title = {{{Reputationssysteme und Gerichtsverfahren als Wekzeuge zur Sicherstellung von Qualitätsstandards in Transaktionen}}}, year = {{2013}}, } @inproceedings{496, abstract = {{Within reactive topology control, a node determines its adjacent edges of a network subgraph without prior knowledge of its neighborhood. The goal is to construct a local view on a topology which provides certain desired properties such as planarity. During algorithm execution, a node, in general, is not allowed to determine all its neighbors of the network graph. There are well-known reactive algorithms for computing planar subgraphs. However, the subgraphs obtained do not have constant Euclidean spanning ratio. This means that routing along these subgraphs may result in potentially long detours. So far, it has been unknown if planar spanners can be constructed reactively. In this work, we show that at least under the unit disk network model, this is indeed possible, by proposing an algorithm for reactive construction of the partial Delaunay triangulation, which recently turned out to be a spanner. Furthermore, we show that our algorithm is message-optimal as a node will only exchange messages with nodes that are also neighbors in the spanner. The algorithm’s presentation is complemented by a rigorous proof of correctness.}}, author = {{Benter, Markus and Neumann, Florentin and Frey, Hannes}}, booktitle = {{Proceedings of the 32nd IEEE International Conference on Computer Communications (INFOCOM)}}, pages = {{2193--2201}}, title = {{{Reactive Planar Spanner Construction in Wireless Ad Hoc and Sensor Networks}}}, doi = {{10.1109/INFCOM.2013.6567022}}, year = {{2013}}, } @misc{500, author = {{Staschewski, Margarita}}, publisher = {{Universität Paderborn}}, title = {{{Price Formation in the Restaurant Industry - An Empirical Analysis}}}, year = {{2013}}, } @misc{503, author = {{Blix, Andreas}}, publisher = {{Universität Paderborn}}, title = {{{Optimale und adaptive binäre Bäume in Netzwerken}}}, year = {{2013}}, } @inproceedings{507, abstract = {{We study two-party communication in the context of directed dynamic networks that are controlled by an adaptive adversary. This adversary is able to change all edges as long as the networks stay strongly-connected in each round. In this work, we establish a relation between counting the total number of nodes in the network and the problem of exchanging tokens between two communication partners which communicate through a dynamic network. We show that the communication problem for a constant fraction of n tokens in a dynamic network with n nodes is at most as hard as counting the number of nodes in a dynamic network with at most 4n+3 nodes. For the proof, we construct a family of directed dynamic networks and apply a lower bound from two-party communication complexity.}}, author = {{Abshoff, Sebastian and Benter, Markus and Malatyali, Manuel and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 17th International Conference on Principles of Distributed Systems (OPODIS)}}, pages = {{11--22}}, title = {{{On Two-Party Communication Through Dynamic Networks}}}, doi = {{10.1007/978-3-319-03850-6_2}}, year = {{2013}}, } @inproceedings{508, abstract = {{The process of planning a virtual topology for a Wavelength Devision Multiplexing (WDM) network is called Virtual Topology Design (VTD). The goal of VTD is to find a virtual topology that supports forwarding the expected traffic without congestion. In networks with fluctuating, high traffic demands, it can happen that no single topology fits all changing traffic demands occurring over a longer time. Thus, during operation, the virtual topology has to be reconfigured. Since modern networks tend to be large, VTD algorithms have to scale well with increasing network size, requiring distributed algorithms. Existing distributed VTD algorithms, however, react too slowly on congestion for the real-time reconfiguration of large networks. We propose Selfish Virtual Topology Reconfiguration (SVTR) as a new algorithm for distributed VTD. It combines reconfiguring the virtual topology and routing through a Software Defined Network (SDN). SVTR is used for online, on-the-fly network reconfiguration. Its integrated routing and WDM reconfiguration keeps connection disruption due to network reconfiguration to a minimum and is able to react very quickly to traffic pattern changes. SVTR works by iteratively adapting the virtual topology to the observed traffic patterns without global traffic information and without future traffic estimations. We evaluated SVTR by simulation and found that it significantly lowers congestion in realistic networks and high load scenarios.}}, author = {{Wette, Philip and Karl, Holger}}, booktitle = {{Proceedings of the 19th IEEE International Workshop on Local and Metropolitan Area Networks (IEEE LANMAN)}}, pages = {{1 -- 6 }}, title = {{{On the Quality of Selfish Virtual Topology Reconfiguration in IP-over-WDM Networks}}}, doi = {{10.1109/LANMAN.2013.6528271}}, year = {{2013}}, } @inproceedings{509, abstract = {{In this paper we will introduce a new d-dimensional graph for constructing geometric application layer overlay net-works. Our approach will use internet coordinates, embedded using the L∞ -metric. After describing the graph structure, we will show how it limits maintenance overhead by bounding each node’s out-degree and how it supports greedy routing using one-hop neighbourhood information in each routing step. We will further show that greedy routing can always compute a path in our graph and we will also prove that in each forwarding step the next hop is closer to the destination than the current node.}}, author = {{Autenrieth, Marcus and Frey, Hannes}}, booktitle = {{Proceedings of the Conference on Networked Systems (NetSys)}}, pages = {{126--131}}, title = {{{On Greedy Routing in Degree-bounded Graphs over d-Dimensional Internet Coordinate Embeddings}}}, doi = {{10.1109/NetSys.2013.10}}, year = {{2013}}, } @misc{510, author = {{Jayesh Parekh, Chintan}}, publisher = {{Universität Paderborn}}, title = {{{Meta-data based Search in Structured Peer-to-Peer Networks}}}, year = {{2013}}, } @misc{511, author = {{Splietker, Malte}}, publisher = {{Universität Paderborn}}, title = {{{MapReduce in Software Defined Networks}}}, year = {{2013}}, } @misc{512, author = {{Herzog, Elvira}}, publisher = {{Universität Paderborn}}, title = {{{Lösungsverfahren für das many-to-one Matching Problem}}}, year = {{2013}}, } @inproceedings{513, abstract = {{This paper initiates the study of self-adjusting networks (or distributed data structures) whose topologies dynamically adapt to a communication pattern $\sigma$. We present a fully decentralized self-adjusting solution called SplayNet. A SplayNet is a distributed generalization of the classic splay tree concept. It ensures short paths (which can be found using local-greedy routing) between communication partners while minimizing topological rearrangements. We derive an upper bound for the amortized communication cost of a SplayNet based on empirical entropies of $\sigma$, and show that SplayNets have several interesting convergence properties. For instance, SplayNets features a provable online optimality under special requests scenarios. We also investigate the optimal static network and prove different lower bounds for the average communication cost based on graph cuts and on the empirical entropy of the communication pattern $\sigma$. From these lower bounds it follows, e.g., that SplayNets are optimal in scenarios where the requests follow a product distribution as well. Finally, this paper shows that in contrast to the Minimum Linear Arrangement problem which is generally NP-hard, the optimal static tree network can be computed in polynomial time for any guest graph, despite the exponentially large graph family. We complement our formal analysis with a small simulation study on a Facebook graph.}}, author = {{Avin, Chen and Häupler, Bernhard and Lotker, Zvi and Scheideler, Christian and Schmid, Stefan}}, booktitle = {{Proceedings of the 27th IEEE International Parallel and Distributed Processing Symposium (IPDPS)}}, pages = {{395--406}}, title = {{{Locally Self-Adjusting Tree Networks}}}, doi = {{10.1109/IPDPS.2013.40}}, year = {{2013}}, } @phdthesis{514, abstract = {{Diese Arbeit besch{\"a}ftigt sich mit dem Facility Location Problem. Dies ist ein Optimierungsproblem, bei dem festgelegt werden muss an welchen Positionen Ressourcen zur Verf{\"u}gung gestellt werden, so dass diese von Nutzern gut erreicht werden k{\"o}nnen. Es sollen dabei Kosten minimiert werden, die zum einen durch Bereitstellung von Ressourcen und zum anderen durch Verbindungskosten zwischen Nutzern und Ressourcen entstehen. Die Schwierigkeit des Problems liegt darin, dass man einerseits m{\"o}glichst wenige Ressourcen zur Verf{\"u}gung stellen m{\"o}chte, andererseits daf{\"u}r sorgen muss, dass sich Nutzer nicht all zu weit weg von Ressourcen befinden. Dies w{\"u}rde n{\"a}mlich hohe Verbindungskosten nach sich ziehen. Das Facility Location Problem wurde bereits sehr intensiv in vielen unterschiedlichen Varianten untersucht. In dieser Arbeit werden drei Varianten des Problems modelliert und neue Algorithmen f{\"u}r sie entwickelt und bez{\"u}glich ihres Approximationsfaktors und ihrer Laufzeit analysiert. Jede dieser drei untersuchten Varianten hat einen besonderen Schwerpunkt. Bei der ersten Varianten handelt es sich um ein Online Problem, da hier die Eingabe nicht von Anfang an bekannt ist, sondern Schritt f{\"u}r Schritt enth{\"u}llt wird. Die Schwierigkeit hierbei besteht darin unwiderrufliche Entscheidungen treffen zu m{\"u}ssen ohne dabei die Zukunft zu kennen und trotzdem eine zu jeder Zeit gute L{\"o}sung angeben zu k{\"o}nnen. Der Schwerpunkt der zweiten Variante liegt auf Lokalit{\"a}t, die z.B. in Sensornetzwerken von großer Bedeutung ist. Hier soll eine L{\"o}sung verteilt und nur mit Hilfe von lokalen Information berechnet werden. Schließlich besch{\"a}ftigt sich die dritte Variante mit einer verteilten Berechnung, bei welcher nur eine stark beschr{\"a}nkte Datenmenge verschickt werden darf und dabei trotzdem ein sehr guter Approximationsfaktor erreicht werden muss. Die bei der Analyse der Approximationsfaktoren bzw. der Kompetitivit{\"a}t verwendeten Techniken basieren zum großen Teil auf Absch{\"a}tzung der primalen L{\"o}sung mit Hilfe einer L{\"o}sung des zugeh{\"o}rigen dualen Problems. F{\"u}r die Modellierung von Lokalit{\"a}t wird das weitverbreitete LOCAL Modell verwendet. In diesem Modell werden f{\"u}r die Algorithmen subpolynomielle obere Laufzeitschranken gezeigt.}}, author = {{Pietrzyk, Peter}}, publisher = {{Universität Paderborn}}, title = {{{Local and Online Algorithms for Facility Location}}}, year = {{2013}}, } @techreport{5146, abstract = {{In this paper, we analyze a model in which two divisions negotiate over an intrafirm transfer price for an intermediate product. Formally, we consider bargaining problems under incomplete information, since the upstream division’s (seller's) costs and downstream division's (buyer's) revenues are supposed to be private information. Assuming two possible types for buyer and seller each, we first establish that the bargaining problem is regular, regardless whether incentive and/or efficiency constraints are imposed. This allows us to apply the generalized Nash bargaining solution to determine transfer payments and transfer probabilities. Furthermore, we derive general properties of this solution for the transfer pricing problem and compare the model developed here with the existing literature for negotiated transfer pricing under incomplete information. In particular, we focus on the models presented in Wagenhofer (1994).}}, author = {{Brangewitz, Sonja and Haake, Claus-Jochen}}, keywords = {{Transfer Pricing, Negotiation, Generalized Nash Bargaining Solution, Incomplete Information}}, publisher = {{CIE Working Paper Series, Paderborn University}}, title = {{{Cooperative Transfer Price Negotiations under Incomplete Information}}}, volume = {{64}}, year = {{2013}}, } @inproceedings{520, abstract = {{Preemptive Routing and Wavelength Assignment (RWA) algorithms preempt established lightpaths in case not enough resources are available to set up a new lightpath in a Wavelength Division Multiplexing (WDM) network. The selection of lightpaths to be preempted relies on internal decisions of the RWA algorithm. Thus, if dedicated properties of the network topology are required by the applications running on the network, these requirements have to be known to the RWA algorithm.Otherwise it might happen that by preempting a particular lightpath these requirements are violated. If, however, these requirements include parametersknown only at the nodes running the application, the RWA algorithm cannot evaluate the requirements. For this reason an RWA algorithm is needed which incorporates feedback from the application layer in the preemption decisions.This work proposes a simple interface along with an algorithm for computing and selecting preemption candidates in case a lightpath cannot be established. We reason about the necessity of using information from the application layer in the RWA and present two example applications which benefit from this idea.}}, author = {{Wette, Philip and Karl, Holger}}, booktitle = {{Proceedings of the 32nd IEEE International Conference on Computer Communications (INFOCOM)}}, pages = {{51--52}}, title = {{{Incorporating feedback from application layer into routing and wavelength assignment algorithms}}}, doi = {{10.1109/INFCOMW.2013.6970733}}, year = {{2013}}, } @misc{522, author = {{Feldotto, Matthias}}, publisher = {{Universität Paderborn}}, title = {{{HSkip+: A Self-Stabilizing Overlay Network for Nodes with Heterogeneous Bandwidths}}}, year = {{2013}}, }