@inproceedings{393, abstract = {{A fundamental problem for peer-to-peer systems is to maintain connectivity while nodes are leaving, i.e., the nodes requesting to leave the peer-to-peer system are excluded from the overlay network without affecting its connectivity. There are a number of studies for safe node exclusion if the overlay is in a well-defined state initially. Surprisingly, the problem is not formally studied yet for the case in which the overlay network is in an arbitrary initial state, i.e., when looking for a self-stabilizing solution for excluding leaving nodes. We study this problem in two variants: the Finite Departure Problem (FDP) ) and the Finite Sleep Problem (FSP). In the FDP the leaving nodes have to irrevocably decide when it is safe to leave the network, whereas in the FSP, this leaving decision does not have to be final: the nodes may resume computation if necessary. We show that there is no self-stabilizing distributed algorithm for the FDP, even in a synchronous message passing model. To allow a solution, we introduce an oracle called NIDEC and show that it is sufficient even for the asynchronous message passing model by proposing an algorithm that can solve the FDP using NIDEC. We also show that a solution to the FSP does not require an oracle.}}, author = {{Foreback, Dianne and Koutsopoulos, Andreas and Nesterenko, Mikhail and Scheideler, Christian and Strothmann, Thim Frederik}}, booktitle = {{Proceedings of the 16th International Symposium on Stabilization, Safety, and Security of Distributed Systems}}, pages = {{48----62}}, title = {{{On Stabilizing Departures in Overlay Networks}}}, doi = {{10.1007/978-3-319-11764-5_4}}, year = {{2014}}, } @inproceedings{395, abstract = {{We consider a multilevel network game, where nodes can improvetheir communication costs by connecting to a high-speed network.The n nodes are connected by a static network and each node can decideindividually to become a gateway to the high-speed network. The goalof a node v is to minimize its private costs, i.e., the sum (SUM-game) ormaximum (MAX-game) of communication distances from v to all othernodes plus a fixed price α > 0 if it decides to be a gateway. Between gatewaysthe communication distance is 0, and gateways also improve othernodes’ distances by behaving as shortcuts. For the SUM-game, we showthat for α ≤ n − 1, the price of anarchy is Θ (n/√α) and in this rangeequilibria always exist. In range α ∈ (n−1, n(n−1)) the price of anarchyis Θ(√α), and for α ≥ n(n − 1) it is constant. For the MAX-game, weshow that the price of anarchy is either Θ (1 + n/√α), for α ≥ 1, orelse 1. Given a graph with girth of at least 4α, equilibria always exist.Concerning the dynamics, both games are not potential games. For theSUM-game, we even show that it is not weakly acyclic.}}, author = {{Abshoff, Sebastian and Cord-Landwehr, Andreas and Jung, Daniel and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Web and Internet Economics (WINE)}}, pages = {{435--440}}, title = {{{Multilevel Network Games}}}, doi = {{10.1007/978-3-319-13129-0_36}}, year = {{2014}}, } @inproceedings{397, abstract = {{We present a factor $14D^2$ approximation algorithm for the minimum linear arrangement problem on series-parallel graphs, where $D$ is the maximum degree in the graph. Given a suitable decomposition of the graph, our algorithm runs in time $O(|E|)$ and is very easy to implement. Its divide-and-conquer approach allows for an effective parallelization. Note that a suitable decomposition can also be computed in time $O(|E|\log{|E|})$ (or even $O(\log{|E|}\log^*{|E|})$ on an EREW PRAM using $O(|E|)$ processors). For the proof of the approximation ratio, we use a sophisticated charging method that uses techniques similar to amortized analysis in advanced data structures. On general graphs, the minimum linear arrangement problem is known to be NP-hard. To the best of our knowledge, the minimum linear arrangement problem on series-parallel graphs has not been studied before.}}, author = {{Scheideler, Christian and Eikel, Martina and Setzer, Alexander}}, booktitle = {{Proceedings of the 12th Workshop on Approximation and Online Algorithms (WAOA)}}, pages = {{168----180}}, title = {{{Minimum Linear Arrangement of Series-Parallel Graphs}}}, year = {{2014}}, } @misc{403, author = {{Martin Lohre, Tobias}}, publisher = {{Universität Paderborn}}, title = {{{Machtverteilungen von Koalitionen im Fokus der politischen Realität}}}, year = {{2014}}, } @misc{404, author = {{van Straaten, Dirk}}, publisher = {{Universität Paderborn}}, title = {{{Kooperative Verhandlungen im duopolistischen Wettbewerb - eine spieltheoretische Analyse}}}, year = {{2014}}, } @misc{405, author = {{Degraf, Olga}}, publisher = {{Universität Paderborn}}, title = {{{Koalitionsbildung bei mehrdimensionalen Verhandlungsproblemen}}}, year = {{2014}}, } @article{410, abstract = {{One goal of service-oriented computing is to realize future markets of composed services. In such markets, service providers offer services that can be flexibly combined with each other. However, although crucial for decision-making, market participants are usually not able to individually estimate the quality of traded services in advance. To overcome this problem, we present a conceptual design for a reputation system that collects and processes user feedback on transactions, and provides this information as a signal for quality to participants in the market. Based on our proposed concept, we describe the incorporation of reputation information into distinct decision-making processes that are crucial in such service markets. In this context, we present a fuzzy service matching approach that takes reputation information into account. Furthermore, we introduce an adaptive service composition approach, and investigate the impact of exchanging immediate user feedback by reputation information. Last but not least, we describe the importance of reputation information for economic decisions of different market participants. The overall output of this paper is a comprehensive view on managing and exploiting reputation information in markets of composed services using the example of On-The-Fly Computing.}}, author = {{Jungmann, Alexander and Brangewitz, Sonja and Petrlic, Ronald and Platenius, Marie Christin}}, journal = {{International Journal On Advances in Intelligent Systems (IntSys)}}, number = {{3&4}}, pages = {{572----594}}, publisher = {{IARIA}}, title = {{{Incorporating Reputation Information into Decision-Making Processes in Markets of Composed Services}}}, volume = {{7}}, year = {{2014}}, } @inproceedings{412, abstract = {{In this paper we present and analyze HSkip+, a self-stabilizing overlay network for nodes with arbitrary heterogeneous bandwidths. HSkip+ has the same topology as the Skip+ graph proposed by Jacob et al. [PODC 2009] but its self-stabilization mechanism significantly outperforms the self-stabilization mechanism proposed for Skip+. Also, the nodes are now ordered according to their bandwidths and not according to their identifiers. Various other solutions have already been proposed for overlay networks with heterogeneous bandwidths, but they are not self-stabilizing. In addition to HSkip+ being self-stabilizing, its performance is on par with the best previous bounds on the time and work for joining or leaving a network of peers of logarithmic diameter and degree and arbitrary bandwidths. Also, the dilation and congestion for routing messages is on par with the best previous bounds for such networks, so that HSkip+ combines the advantages of both worlds. Our theoretical investigations are backed by simulations demonstrating that HSkip+ is indeed performing much better than Skip+ and working correctly under high churn rates.}}, author = {{Feldotto, Matthias and Scheideler, Christian and Graffi, Kalman}}, booktitle = {{Proceedings of the 14th IEEE International Conference on Peer-to-Peer Computing (P2P)}}, pages = {{1--10}}, title = {{{HSkip+: A Self-Stabilizing Overlay Network for Nodes with Heterogeneous Bandwidths}}}, doi = {{10.1109/P2P.2014.6934300}}, year = {{2014}}, } @misc{413, author = {{Eusterholz, Fabian}}, publisher = {{Universität Paderborn}}, title = {{{Horizontale Fusionen: Theorie und Praxis am Beispiel zweier Entscheidungen des Bundeskartellamtes}}}, year = {{2014}}, } @phdthesis{419, abstract = {{The present thesis investigates the prevalence of and the reasons for hiring discrimination against women and ethnic Turks in the German labor market. Subsequent to a discussion of how to reveal discrimination, the literature on wage and employment differences inside and outside the German labor market is reviewed. Afterwards, different (economic) theories explaining inequalities in labor markets are presented. In the empirical analyses a field experiment - the so called correspondence testing - is conducted where matched pairs of (fictitious) male and female as well as German-named and Turkish-named applicants respond to, respectively, 656 and 608 (real) apprenticeship offers in predominantly male-dominated jobs. Descriptive results and econometric analyses using probit regressions on various model specifications indicate that the female applicant has a 19 percent lower callback probability compared to her male counterpart. However, differential treatment is both job- and firm-type driven. While callback rates are not statistically different from zero in female-dominated and “gender-neutral” occupations, they prevail in jobs where men are overrepresented. Furthermore, discrimination is restricted to late recruiters, i.e., companies that advertise their vacancies right before the apprenticeship is supposed to start. Similar conclusions can be drawn from the study investigating ethnic discrimination. The 32 percent lower callback probability of the Turkish-named applicant decreases if early rather than late recruiters are addressed. Apart from that, comparing response and callback rates to the candidates using different experimental designs, i.e., sending out single versus pairs of applications, yields no statistically significant differences demonstrating the unbiasedness of the correspondence approach.}}, author = {{Kolle, Andre}}, publisher = {{Universität Paderborn}}, title = {{{Gender and ethnic discrimination in hiring : evidence from field experiments in the German labor market}}}, year = {{2014}}, } @misc{426, author = {{Dornseifer, Veit}}, publisher = {{Universität Paderborn}}, title = {{{Evaluation of a Hybrid Packet-/Circuit-Switched Data Center Network}}}, year = {{2014}}, } @misc{432, author = {{Bredenbals, Nico}}, publisher = {{Universität Paderborn}}, title = {{{Energy-Efficient Queuing with Delayed Deactivation}}}, year = {{2014}}, } @misc{434, author = {{Luo, Linghui}}, publisher = {{Universität Paderborn}}, title = {{{Ein selbst-stabilisierender Algorithmus für das Finite Sleep Problem in Skip+ Graphen}}}, year = {{2014}}, } @misc{437, author = {{Wemhöner, Vanessa}}, publisher = {{Universität Paderborn}}, title = {{{Die ökonomischen Auswirkungen der Kronzeugenregelung am Beispiel des Kaffeerösterkartells}}}, year = {{2014}}, } @phdthesis{440, author = {{Kaimann, Daniel}}, publisher = {{Universität Paderborn}}, title = {{{Decision Making under Asymmetric Information in Markets for Experience Goods: Empirical Evidence of Signaling Effects on Consumer Perceptions}}}, year = {{2014}}, } @article{2543, author = {{Brangewitz, Sonja and Gamp, Jan-Philip}}, issn = {{0165-1765}}, journal = {{Economics Letters}}, number = {{2}}, pages = {{224--227}}, publisher = {{Elsevier}}, title = {{{Asymmetric Nash bargaining solutions and competitive payoffs}}}, doi = {{10.1016/j.econlet.2013.08.013}}, volume = {{121}}, year = {{2013}}, } @misc{18000, author = {{Blumentritt, Fritz}}, publisher = {{Universität Paderborn}}, title = {{{Cliquenbildung in verteilten Systemen}}}, year = {{2013}}, } @inproceedings{470, abstract = {{In OpenFlow [1], multiple switches share the same control plane which is centralized atwhat is called the OpenFlow controller. A switch only consists of a forwarding plane. Rules for forwarding individual packets (called ow entries in OpenFlow) are pushed from the controller to the switches. In a network with a high arrival rate of new ows, such as in a data center, the control trac between the switch and controller can become very high. As a consequence, routing of new ows will be slow. One way to reduce control trac is to use wildcarded ow entries. Wildcard ow entries can be used to create default routes in the network. However, since switches do not keep track of ows covered by a wildcard ow entry, the controller no longer has knowledge about individual ows. To nd out about these individual ows we propose an extension to the current OpenFlow standard to enable packet sampling of wildcard ow entries.}}, author = {{Wette, Philip and Karl, Holger}}, booktitle = {{Proceedings of the ACM SIGCOMM '13}}, pages = {{541--542}}, title = {{{Which Flows Are Hiding Behind My Wildcard Rule? Adding Packet Sampling to OpenFlow}}}, doi = {{10.1145/2486001.2491710}}, year = {{2013}}, } @techreport{474, abstract = {{Suppose some individuals are allowed to engage in different groups at the same time and they generate a certain welfare by cooperation. Finding appropriate ways for distributing this welfare is a non-trivial issue. The purpose of this work is to analyze two-stage allocation procedures where first each group receives a share of the welfare which is then, subsequently, distributed among the corresponding members. To study these procedures in a structured way, cooperative games and network games are combined in a general framework by using mathematical hypergraphs. Moreover, several convincing requirements on allocation procedures are discussed and formalized. Thereby it will be shown, for example, that the Position Value and iteratively applying the Myerson Value can be characterized by similar axiomatizations.}}, author = {{Röhl, Nils}}, publisher = {{Universität Paderborn}}, title = {{{Two-Stage Allocation Procedures}}}, year = {{2013}}, } @article{476, abstract = {{An elementary h-route ow, for an integer h 1, is a set of h edge- disjoint paths between a source and a sink, each path carrying a unit of ow, and an h-route ow is a non-negative linear combination of elementary h-routeows. An h-route cut is a set of edges whose removal decreases the maximum h-route ow between a given source-sink pair (or between every source-sink pair in the multicommodity setting) to zero. The main result of this paper is an approximate duality theorem for multicommodity h-route cuts and ows, for h 3: The size of a minimum h-route cut is at least f=h and at most O(log4 k f) where f is the size of the maximum h-routeow and k is the number of commodities. The main step towards the proof of this duality is the design and analysis of a polynomial-time approximation algorithm for the minimum h-route cut problem for h = 3 that has an approximation ratio of O(log4 k). Previously, polylogarithmic approximation was known only for h-route cuts for h 2. A key ingredient of our algorithm is a novel rounding technique that we call multilevel ball-growing. Though the proof of the duality relies on this algorithm, it is not a straightforward corollary of it as in the case of classical multicommodity ows and cuts. Similar results are shown also for the sparsest multiroute cut problem.}}, author = {{Kolman, Petr and Scheideler, Christian}}, journal = {{Theory of Computing Systems}}, number = {{2}}, pages = {{341--363}}, publisher = {{Springer}}, title = {{{Towards Duality of Multicommodity Multiroute Cuts and Flows: Multilevel Ball-Growing}}}, doi = {{10.1007/s00224-013-9454-3}}, year = {{2013}}, }