TY - CONF AU - Volkhausen, Tobias AU - Dridger, Kornelius AU - S. Lichte, Hermann AU - Karl, Holger ID - 792 T2 - 10th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt), Paderborn, Germany, May 14-18, 2012 TI - Efficient cooperative relaying in wireless multi-hop networks with commodity WiFi hardware ER - TY - CONF AU - Becker, Matthias AU - Luckey, Markus AU - Becker, Steffen ID - 8055 T2 - Proceedings of the International Conference on Quality of Software Architecture TI - Model-driven Performance Engineering of Self-Adaptive Systems: A Survey ER - TY - CONF AB - Service-oriented computing (SOC) promises to solve many issues in the area of distributed software development, e.g. the realization of the loose coupling pattern in practice through service discovery and invocation. For this purpose, service descriptions must comprise structural as well as behavioral information of the services otherwise an accurate service discovery is not possible. We addressed this issue in our previous paper and proposed a UML-based rich service description language (RSDL) providing comprehensive notations to specify service requests and offers. However, the automatic matching of service requests and offers specified in a RSDL for the purpose of service discovery is a complex task, due to multifaceted heterogeneity of the service partners. This heterogeneity includes the use of different underlying ontologies or different levels of granularity in the specification itself resulting in complex mappings between service requests and offers. In this paper, we present an automatic matching mechanism for service requests and offers specified in a RSDL that overcomes the underlying heterogeneity of the service partners. AU - Huma, Zille AU - Gerth, Christian AU - Engels, Gregor AU - Juwig, Oliver ID - 8056 T2 - Proceedings of the ACM/IEEE 15th International Conference on Model Driven Engineering Languages and Systems (MODELS'12) TI - Towards an Automatic Service Discovery for UML-based Rich Service Descriptions VL - 7590 ER - TY - BOOK AU - Kremer, Marion AU - Engels, Gregor AU - Hofmann, Alexander AU - Hohwiller, Jörg AU - E. Nandico, Oliver AU - Nötzold, Thomas AU - Prott, Karl AU - Schlegel, Diethelm AU - Seidl, Andreas AU - Wolf, Thomas ID - 8226 TI - Quasar 3.0 - A Situational Approach to Software Engineering ER - TY - CONF AB - A major goal of the On-The-Fly Computing project is the automated composition of individual services based on services that are available in dynamic markets. Dependent on the granularity of a market, different alternatives that satisfy the requested functional requirements may emerge. In order to select the best solution, services are usually selected with respect to their quality in terms of inherent non-functional properties. In this paper, we describe our idea of how to model this service selection process as a Markov Decision Process, which we in turn intend to solve by means of Reinforcement Learning techniques in order to control the underlying service composition process. In addition, some initial issues with respect to our approach are addressed. AU - Jungmann, Alexander AU - Kleinjohann, Bernd ID - 568 T2 - Proceedings of the 9th IEEE International Conference on Service Computing (SCC) TI - Towards the Application of Reinforcement Learning Techniques for Quality-Based Service Selection in Automated Service Composition ER - TY - CONF AU - Püschel, Tim AU - Schryen, Guido AU - Hristova, Diana AU - Neumann, Dirk ID - 5680 T2 - European Conference on Information Systems TI - Cloud Service Revenue Management ER - TY - CONF AU - Lang, Fabian AU - Schryen, Guido AU - Fink, Andreas ID - 5683 T2 - International Conference on Information Systems TI - Elicitating, modeling, and processing uncertain human preferences for software agents in electronic negotiations: An empirical study ER - TY - JOUR AU - Bodenstein, Christian AU - Schryen, Guido AU - Neumann, Dirk ID - 5688 IS - 1 JF - European Journal of Operational Research : EJOR TI - Energy-Aware Workload Management Models for Operating Cost Reduction in Data Centers VL - 222 ER - TY - CONF AB - Today's real-time embedded systems operate in frequently changing environments on which they react by self-adaptations. Such an approach needs adequate modeling support of these reconfigurations to enable verification of safety properties, e.g., by timed model checking. Component-based development of such systems realizes these self-adaptations by structural reconfigurations of components and their connectors. However, component models proposed in literature do not support reconfigurable components in real-time embedded context but focus on other domains like business information systems. In this paper, we present an extension of our modeling language MechatronicUML to support structural reconfigurations taking the specific requirements of our domain into account. Based on the proposed extension we outline our research roadmap to achieve verification and realization of systems modeled in MechatronicUML. AU - Becker, Steffen AU - Heinzemann, Christian AU - Priesterjahn, Claudia ID - 569 T2 - Proceedings of the 15th ACM SigSoft International Symposium on Component-Based Software Engineering (CBSE) TI - Towards Modeling Reconfiguration in Hierarchical Component Architectures ER - TY - JOUR AB - This article studies the construction of self-stabilizing topologies for distributed systems. While recent research has focused on chain topologies where nodes need to be linearized with respect to their identiers, we explore a natural and relevant 2-dimensional generalization. In particular, we present a local self-stabilizing algorithm DStab which is based on the concept of \local Delaunay graphs" and which forwards temporary edges in greedy fashion reminiscent of compass routing. DStab constructs a Delaunay graph from any initial connected topology and in a distributed manner in time O(n3) in the worst-case; if the initial network contains the Delaunay graph, the convergence time is only O(n) rounds. DStab also ensures that individual node joins and leaves aect a small part of the network only. Such self-stabilizing Delaunay networks have interesting applications and our construction gives insights into the necessary geometric reasoning that is required for higherdimensional linearization problems.Keywords: Distributed Algorithms, Topology Control, Social Networks AU - Jacob, Riko AU - Ritscher, Stephan AU - Scheideler, Christian AU - Schmid, Stefan ID - 570 JF - Theoretical Computer Science TI - Towards higher-dimensional topological self-stabilization: A distributed algorithm for Delaunay graphs ER - TY - CONF AB - The paradigm shift from purchasing monolithic software solutions to a dynamic composition of individual solutions entails many new possibilities yet great challenges, too. In order to satisfy user requirements, complex services have to be automatically composed of elementary services. Multiple possibilities of composing a complex service inevitably emerge. The problem of selecting the most appropriate services has to be solved by comparing the different service candidates with respect to their quality in terms of inherent non-functional properties while simultaneously taking the user requirements into account. We are aiming for an integrated service rating and ranking methodology in order to support the automation of the underlying decision-making process. The main contribution of this paper is a first decomposition of the quality-based service selection process, while emphasizing major issues and challenges, which we are addressing in the On-The-Fly Computing project. AU - Jungmann, Alexander AU - Kleinjohann, Bernd ID - 571 T2 - Proceedings of the 4th International Conferences on Advanced Service Computing (SERVICE COMPUTATION) TI - Towards an Integrated Service Rating and Ranking Methodology for Quality Based Service Selection in Automatic Service Composition ER - TY - JOUR AB - The tendency of managers to focus on short-term results rather than on sustained company success is of particular importance to retail marketing managers, because marketing activities involve expenditures which may only pay off in the longer term. To address the issue of myopic management, our study shows how the complexity of the service profit chain (SPC) can cause managers to make suboptimal decisions. Hence, our paper departs from past research by recognizing that understanding the temporal interplay between operational investments, employee satisfaction, customer satisfaction, and operating profit is essential to achieving sustained success. In particular, we intend to improve understanding of the functioning of the SPC with respect to time lags and feedback loops. Results of our large-scale longitudinal study set in a multi-outlet retail chain reveal time-lag effects between operational investments and employee satisfaction, as well as between customer satisfaction and performance. These findings, along with evidence of a negative interaction effect of employee satisfaction on the relationship between current performance and future investments, show the substantial risk of mismanaging the SPC. We identify specific situations in which the dynamic approach leads to superior marketing investment decisions, when compared to the conventional static view of the SCP. These insights provide valuable managerial guidance for effectively managing the SPC over time. AU - Evanschitzky, Heiner AU - Wangenheim, Florian v AU - Wünderlich, Nancy ID - 5716 IS - 3 JF - Journal of Retailing KW - Employee satisfaction KW - Customer satisfaction KW - Performance KW - Service profit chain KW - Feedback loops KW - Time lags KW - Myopic marketing management TI - Perils of Managing the Service Profit Chain: The Role of Time Lags and Feedback Loops. VL - 88 ER - TY - JOUR AB - Although professional service providers increasingly deliver their services globally, little is known about cross-cultural differences in customers’ motivation to participate in service production. To address this lacuna, we survey a total of 2,284 banking customers in 11 countries on their motivation to provide personal information to, and follow the advice of, their service providers. We find differences in both aspects, but only the differences in providing personal information can be explained by the cultural values of uncertainty avoidance, individualism/collectivism, and masculinity/femininity. To perform certain tasks in the service process, global professional service providers should acknowledge cultural differences in customers’ motivations. AU - Schumann, Jan H AU - Wünderlich, Nancy AU - Zimmer, Marcus S ID - 5717 IS - 2 JF - Schmalenbach Business Review KW - Co-Production KW - Culture KW - Customer Participation KW - Professional Services TI - Culture’s Impact on Customer Motivation to Engage in Professional Service Enactments. VL - 64 ER - TY - JOUR AB - The role of information and communication technology for economic growth has been emphasized repeatedly. Technological breakthroughs have generated new forms of services, such as self-services or remote services. Although these encounters are qualitatively different from traditional service provision, prior service management literature thus far had paid little attention to theory development and the systematization of technology-based service encounters. To fill this research gap, the present study outlines how new types of technology-based services fit into existing service typologies and provides an extension of existing frameworks to capture their unique characteristics. These insights in turn offer managerial implications and highlight open research questions. AU - Schumann, Jan H AU - Wünderlich, Nancy AU - Wangenheim, Florian ID - 5718 IS - 2 JF - Technovation KW - Services KW - Remote services KW - Self-services KW - Technology mediation TI - Technology Mediation in Service Delivery: A New Typology and an Agenda for Managers and Academics. VL - 32 ER - TY - CONF AB - Service-oriented computing (SOC) promises to solve many issues in the area of distributed software development, e.g. the realization of the loose coupling pattern in practice through service discovery and invocation. For this purpose, service descriptions must comprise structural as well as behavioral information of the services otherwise an accurate service discovery is not possible. We addressed this issue in our previous paper and proposed a UML-based rich service description language (RSDL) providing comprehensive notations to specify service requests and offers.However, the automatic matching of service requests and offers specified in a RSDL for the purpose of service discovery is a complex task, due to multifaceted heterogeneity of the service partners. This heterogeneity includes the use of different underlying ontologies or different levels of granularity in the specification itself resulting in complex mappings between service requests and offers. In this paper, we present an automatic matching mechanism for service requests and offers specified in a RSDL that overcomes the underlying heterogeneity of the service partners. AU - Huma, Zille AU - Gerth, Christian AU - Engels, Gregor AU - Juwig, Oliver ID - 572 T2 - Proceedings of the ACM/IEEE 15th International Conference on Model Driven Engineering Languages and Systems (MoDELS) TI - Towards an Automatic Service Discovery for UML-based Rich Service Descriptions ER - TY - CONF AB - In software markets of the future, customer-specific software will be developed on demand from distributed software and hardware services available on world-wide markets. Having a request, services have to be automatically discovered and composed. For that purpose, services have to be matched based on their specifications. For the accurate matching, services have to be described comprehensively that requires the integration of different domain-specific languages (DSLs) used for functional, non-functional, and infrastructural properties. Since different service providers use plenty of language dialects to model the same service property, their integration is needed for the matching. In this paper, we propose a framework for integration of DSLs. It is based on a parameterized abstract core language that integrates key concepts needed to describe a service. Parts of the core language can be substituted with concrete DSLs. Thus, the framework serves as a basis for the comprehensive specification and automatic matching of services. AU - Arifulina, Svetlana ED - W. Eisenecker, Ulrich ED - Bucholdt, Christian ID - 573 T2 - Proceedings of the Doctoral Symposium of the 5th International Conference on Software Language Engineering 2012, Dresden, Germany (SLE (Doctoral Symposium)) TI - Towards a Framework for the Integration of Modeling Languages ER - TY - JOUR AB - We present Tiara — a self-stabilizing peer-to-peer network maintenance algorithm. Tiara is truly deterministic which allows it to achieve exact performance bounds. Tiara allows logarithmic searches and topology updates. It is based on a novel sparse 0-1 skip list. We then describe its extension to a ringed structure and to a skip-graph.Key words: Peer-to-peer networks, overlay networks, self-stabilization. AU - Clouser, Thomas AU - Nesterenko, Mikhail AU - Scheideler, Christian ID - 574 JF - Theoretical Computer Science TI - Tiara: A self-stabilizing deterministic skip list and skip graph ER - TY - GEN AU - Bremer, Lars ID - 575 TI - Symbiotic Coupling of Peer-to-Peer and Cloud Systems ER - TY - CONF AU - Nagel, Benjamin AU - Gerth, Christian AU - Yigitbas, Enes AU - Christ, Fabian AU - Engels, Gregor ID - 5753 T2 - Proceedings of the 1st International Workshop on Model-Driven Engineering for High Performance and CLoud computing co-located with 15th International Conference on Model Driven Engineering Languages and Systems {(MODELS} 2012), Innsbruck, Austria, October 01 - 05, 2012 TI - Model-driven specification of adaptive cloud-based systems ER - TY - GEN AU - Schmitz, Henning ID - 576 TI - Stereo Matching on a Convey HC-1 Hybrid Core Computer ER -