TY - JOUR A1 - Dyck, Johannes A1 - Giese, Holger A1 - Lambers, Leen T1 - Automatic verification of behavior preservation at the transformation level for relational model transformation JF - Software and systems modeling N2 - The correctness of model transformations is a crucial element for model-driven engineering of high-quality software. In particular, behavior preservation is an important correctness property avoiding the introduction of semantic errors during the model-driven engineering process. Behavior preservation verification techniques show some kind of behavioral equivalence or refinement between source and target model of the transformation. Automatic tool support is available for verifying behavior preservation at the instance level, i.e., for a given source and target model specified by the model transformation. However, until now there is no sound and automatic verification approach available at the transformation level, i.e., for all source and target models. In this article, we extend our results presented in earlier work (Giese and Lambers, in: Ehrig et al (eds) Graph transformations, Springer, Berlin, 2012) and outline a new transformation-level approach for the sound and automatic verification of behavior preservation captured by bisimulation resp.simulation for outplace model transformations specified by triple graph grammars and semantic definitions given by graph transformation rules. In particular, we first show how behavior preservation can be modeled in a symbolic manner at the transformation level and then describe that transformation-level verification of behavior preservation can be reduced to invariant checking of suitable conditions for graph transformations. We demonstrate that the resulting checking problem can be addressed by our own invariant checker for an example of a transformation between sequence charts and communicating automata. KW - Relational model transformation KW - Formal verification of behavior preservation KW - Behavioral equivalence and refinement KW - Bisimulation and simulation KW - Graph transformation KW - Triple graph grammars KW - Invariant checking Y1 - 2018 U6 - https://doi.org/10.1007/s10270-018-00706-9 SN - 1619-1366 SN - 1619-1374 VL - 18 IS - 5 SP - 2937 EP - 2972 PB - Springer CY - Heidelberg ER - TY - GEN A1 - Hölzle, Katharina A1 - Björk, Jennie A1 - Visscher, Klaasjan T1 - Editorial T2 - Creativity and innovation management N2 - The new year starts and many of us have right away been burdened with conference datelines, grant proposal datelines, teaching obligations, paper revisions and many other things. While being more or less successful in fulfilling To‐Do lists and ticking of urgent (and sometimes even important) things, we often feel that our ability to be truly creative or innovative is rather restrained by this (external pressure). With this, we are not alone. Many studies have shown that stress does influence overall work performance and satisfaction. Furthermore, more and more students and entry‐levels look for work‐life balance and search for employers that offer a surrounding and organization considering these needs. High‐Tech and start‐up companies praise themselves for their “Feel‐Good managers” or Yoga programs. But is this really helpful? Is there indeed a relationship between stress, adverse work environment and creativity or innovation? What are the supporting factors in a work environment that lets employees be more creative? What kind of leadership do we need for innovative behaviour and to what extent can an organization create support structures that reduce the stress we feel? The first issue of Creativity and Innovation Management in 2019 gives some first answers to these questions and hopefully some food for thought. The first paper written by Dirk De Clercq, and Imanol Belausteguigoitia starts with the question which impact work overload has on creative behaviour. The authors look at how employees' perceptions of work overload reduces their creative behaviour. While they find empirical proof for this relationship, they can also show that the effect is weaker with higher levels of passion for work, emotion sharing, and organizational commitment. The buffering effects of emotion sharing and organizational commitment are particularly strong when they are combined with high levels of passion for work. Their findings give first empirical proof that organizations can and should take an active role in helping their employees reducing the effects of adverse work conditions in order to become or stay creative. However, not only work overload is harming creative behaviour, also the fear of losing one's job has detrimental effects on innovative work behaviour. Anahi van Hootegem, Wendy Niesen and Hans de Witte verify that stress and adverse environmental conditions shape our perception of work. Using threat rigidity theory and an empirical study of 394 employees, they show that the threat of job loss impairs employees' innovativeness through increased irritation and decreased concentration. Organizations can help their employees coping better with this insecurity by communicating more openly and providing different support structures. Support often comes from leadership and the support of the supervisor can clearly shape an employee's motivation to show creative behaviour. Wenjing Cai, Evgenia Lysova, Bart A. G. Bossink, Svetlana N. Khapova and Weidong Wang report empirical findings from a large‐scale survey in China where they find that supervisor support for creativity and job characteristics effectively activate individual psychological capital associated with employee creativity. On a slight different notion, Gisela Bäcklander looks at agile practices in a very well‐known High Tech firm. In “Doing Complexity Leadership Theory: How agile coaches at Spotify practice enabling leadership”, she researches the role of agile coaches and how they practice enabling leadership, a key balancing force in complexity leadership. She finds that the active involvement of coaches in observing group dynamics, surfacing conflict and facilitating and encouraging constructive dialogue leads to a positive working environment and the well‐being of employees. Quotes from the interviews suggest that the flexible structure provided by the coaches may prove a fruitful way to navigate and balance autonomy and alignment in organizations. The fifth paper of Frederik Anseel, Michael Vandamme, Wouter Duyck and Eric Rietzchel goes a little further down this road and researches how groups can be motivated better to select truly creative ideas. We know from former studies that groups often perform rather poorly when it comes to selecting creative ideas for implementation. The authors find in an extensive field experiment that under conditions of high epistemic motivation, proself motivated groups select significantly more creative and original ideas than prosocial groups. They conclude however, that more research is needed to understand better why these differences occur. The prosocial behaviour of groups is also the theme of Karin Moser, Jeremy F. Dawson and Michael A. West's paper on “Antecedents of team innovation in health care teams”. They look at team‐level motivation and how a prosocial team environment, indicated by the level of helping behaviour and information‐sharing, may foster innovation. Their results support the hypotheses of both information‐sharing and helping behaviour on team innovation. They suggest that both factors may actually act as buffer against constraints in team work, such as large team size or high occupational diversity in cross‐functional health care teams, and potentially turn these into resources supporting team innovation rather than acting as barriers. Away from teams and onto designing favourable work environments, the seventh paper of Ferney Osorio, Laurent Dupont, Mauricio Camargo, Pedro Palominos, Jose Ismael Pena and Miguel Alfaro looks into innovation laboratories. Although several studies have tackled the problem of design, development and sustainability of these spaces for innovation, there is still a gap in understanding how the capabilities and performance of these environments are affected by the strategic intentions at the early stages of their design and functioning. The authors analyse and compare eight existing frameworks from literature and propose a new framework for researchers and practitioners aiming to assess or to adapt innovation laboratories. They test their framework in an exploratory study with fifteen laboratories from five different countries and give recommendations for the future design of these laboratories. From design to design thinking goes our last paper from Rama Krishna Reddy Kummitha on “Design Thinking in Social Organisations: Understanding the role of user engagement” where she studies how users persuade social organisations to adopt design thinking. Looking at four social organisations in India during 2008 to 2013, she finds that the designer roles are blurred when social organisations adopt design thinking, while users in the form of interconnecting agencies reduce the gap between designers and communities. The last two articles were developed from papers presented at the 17th International CINet conference organized in Turin in 2016 by Paolo Neirotti and his colleagues. In the first article, Fábio Gama, Johan Frishammar and Vinit Parida focus on ideation and open innovation in small‐ and medium‐sized enterprises. They investigate the relationship between systematic idea generation and performance and the moderating role of market‐based partnerships. Based on a survey among manufacturing SMEs, they conclude that higher levels of performance are reached and that collaboration with customers and suppliers pays off most when idea generation is done in a highly systematic way. The second article, by Anna Holmquist, Mats Magnusson and Mona Livholts, resonates the theme of the CINet conference ‘Innovation and Tradition; combining the old and the new’. They explore how tradition is used in craft‐based design practices to create new meaning. Applying a narrative ‘research through design’ approach they uncover important design elements, and tensions between them. Please enjoy this first issue of CIM in 2019 and we wish you creativity and innovation without too much stress in the months to come. Y1 - 2019 U6 - https://doi.org/10.1111/caim.12307 SN - 0963-1690 SN - 1467-8691 VL - 28 IS - 1 SP - 3 EP - 4 PB - Wiley CY - Hoboken ER - TY - THES A1 - Nikaj, Adriatik T1 - Restful choreographies T1 - REST-Choreografien N2 - Business process management has become a key instrument to organize work as many companies represent their operations in business process models. Recently, business process choreography diagrams have been introduced as part of the Business Process Model and Notation standard to represent interactions between business processes, run by different partners. When it comes to the interactions between services on the Web, Representational State Transfer (REST) is one of the primary architectural styles employed by web services today. Ideally, the RESTful interactions between participants should implement the interactions defined at the business choreography level. The problem, however, is the conceptual gap between the business process choreography diagrams and RESTful interactions. Choreography diagrams, on the one hand, are modeled from business domain experts with the purpose of capturing, communicating and, ideally, driving the business interactions. RESTful interactions, on the other hand, depend on RESTful interfaces that are designed by web engineers with the purpose of facilitating the interaction between participants on the internet. In most cases however, business domain experts are unaware of the technology behind web service interfaces and web engineers tend to overlook the overall business goals of web services. While there is considerable work on using process models during process implementation, there is little work on using choreography models to implement interactions between business processes. This thesis addresses this research gap by raising the following research question: How to close the conceptual gap between business process choreographies and RESTful interactions? This thesis offers several research contributions that jointly answer the research question. The main research contribution is the design of a language that captures RESTful interactions between participants---RESTful choreography modeling language. Formal completeness properties (with respect to REST) are introduced to validate its instances, called RESTful choreographies. A systematic semi-automatic method for deriving RESTful choreographies from business process choreographies is proposed. The method employs natural language processing techniques to translate business interactions into RESTful interactions. The effectiveness of the approach is shown by developing a prototypical tool that evaluates the derivation method over a large number of choreography models. In addition, the thesis proposes solutions towards implementing RESTful choreographies. In particular, two RESTful service specifications are introduced for aiding, respectively, the execution of choreographies' exclusive gateways and the guidance of RESTful interactions. N2 - Das Prozessmanagement hat sich zu einer wichtigen Methode zur Organisation von Arbeitsabläufen entwickelt, sodass viele Unternehmen ihre Tätigkeiten mittlerweile in Prozessmodellen darstellen. Unlängst wurden zudem im Kontext der Business Process Model and Notation Choreographiediagramme eingeführt, um Interaktionen zwischen Prozessen verschiedener Partner zu beschreiben. Im Web nutzen interagierende Dienste heutzutage den Representational State Transfer (REST) als primären Architekturstil. Idealerweise implementieren die REST-Interaktionen der Dienste also die Interaktionen, die im Choreographiediagramm definiert wurden. Allerdings besteht zwischen Choreographiediagrammen und RESTInteraktionen eine konzeptuelle Diskrepanz. Auf der einen Seite werden Choreographiediagramme von Domänenexperten mit dem Ziel modelliert, die Interaktionen zu erfassen, zu kommunizieren und, idealerweise, voranzutreiben. Auf der anderen Seite sind REST-Interaktionen abhängig von REST-Schnittstellen, welche von Web-Entwicklern mit dem Ziel entworfen werden, Interaktionen zwischen Diensten im Internet zu erleichtern. In den meisten Fällen sind sich Domänenexperten jedoch der Technologien, die Web-Schnittstellen zu Grunde liegen, nicht bewusst, wohingegenWeb-Entwickler die Unternehmensziele der Web-Dienste nicht kennen. Während es umfangreiche Arbeiten zur Implementierung von Prozessmodellen gibt, existieren nur wenige Untersuchungen zur Implementierung von interagierenden Prozessen auf Basis von Choreographiemodellen. Die vorliegende Dissertation adressiert diese Forschungslücke, indem sie die folgende Forschungsfrage aufwirft: Wie kann die konzeptuelle Diskrepanz zwischen Choreographiediagrammen und REST-Interaktionen beseitigt werden? Somit enthält diese Arbeit mehrere Forschungsbeiträge, um diese Frage zu adressieren. Der primäre Beitrag besteht in dem Design einer Modellierungssprache, um REST-Interaktionen zwischen Diensten zu erfassen—der RESTful Choreography Modeling Language. Formale Vollständigkeitseigenschaften (in Bezug auf REST) werden eingeführt, um Instanzen dieser Modelle, sogennante REST-Choreographien, zu validieren. Ferner wird eine systematische, halb-automatische Methode vorgestellt, um RESTChoreographien von Choreographiediagrammen abzuleiten. Diese Methode setzt Techniken des Natural Language Processing ein, um Interaktionen in REST-Interaktionen zu übersetzen. Die Wirksamkeit des Ansatzes wird durch die Entwicklung eines prototypischen Werkzeugs demonstriert, welches die Ableitungsmethode anhand einer großen Anzahl von Choreographiediagrammen evaluiert. Darüber hinaus stellt diese Arbeit Lösungen zur Implementierung von REST-Choreographien bereit. Insbesondere werden zwei REST-Dienstspezifikationen vorgestellt, welche die korrekte Ausführung von exklusiven Gateways eines Choreographiediagramms und die Führung der REST-Interaktionen unterstützen. KW - business process choreographies KW - RESTful interactions KW - Geschäftsprozess-Choreografien KW - REST-Interaktionen Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-438903 ER - TY - GEN A1 - Schlosser, Rainer A1 - Kossmann, Jan A1 - Boissier, Martin T1 - Efficient Scalable Multi-Attribute Index Selection Using Recursive Strategies T2 - 2019 IEEE 35th International Conference on Data Engineering (ICDE) N2 - An efficient selection of indexes is indispensable for database performance. For large problem instances with hundreds of tables, existing approaches are not suitable: They either exhibit prohibitive runtimes or yield far from optimal index configurations by strongly limiting the set of index candidates or not handling index interaction explicitly. We introduce a novel recursive strategy that does not exclude index candidates in advance and effectively accounts for index interaction. Using large real-world workloads, we demonstrate the applicability of our approach. Further, we evaluate our solution end to end with a commercial database system using a reproducible setup. We show that our solutions are near-optimal for small index selection problems. For larger problems, our strategy outperforms state-of-the-art approaches in both scalability and solution quality. Y1 - 2019 SN - 978-1-5386-7474-1 U6 - https://doi.org/10.1109/ICDE.2019.00113 SN - 1084-4627 SP - 1238 EP - 1249 PB - IEEE CY - New York ER - TY - JOUR A1 - Stojanovic, Vladeta A1 - Trapp, Matthias A1 - Richter, Rico A1 - Döllner, Jürgen Roland Friedrich T1 - Service-oriented semantic enrichment of indoor point clouds using octree-based multiview classification JF - Graphical Models N2 - The use of Building Information Modeling (BIM) for Facility Management (FM) in the Operation and Maintenance (O&M) stages of the building life-cycle is intended to bridge the gap between operations and digital data, but lacks the functionality of assessing the state of the built environment due to non-automated generation of associated semantics. 3D point clouds can be used to capture the physical state of the built environment, but also lack these associated semantics. A prototypical implementation of a service-oriented architecture for classification of indoor point cloud scenes of office environments is presented, using multiview classification. The multiview classification approach is tested using a retrained Convolutional Neural Network (CNN) model - Inception V3. The presented approach for classifying common office furniture objects (chairs, sofas and desks), contained in 3D point cloud scans, is tested and evaluated. The results show that the presented approach can classify common office furniture up to an acceptable degree of accuracy, and is suitable for quick and robust semantics approximation - based on RGB (red, green and blue color channel) cubemap images of the octree partitioned areas of the 3D point cloud scan. Additional methods for web-based 3D visualization, editing and annotation of point clouds are also discussed. Using the described approach, captured scans of indoor environments can be semantically enriched using object annotations derived from multiview classification results. Furthermore, the presented approach is suited for semantic enrichment of lower resolution indoor point clouds acquired using commodity mobile devices. KW - Semantic enrichment KW - 3D point clouds KW - Multiview classification KW - Service-oriented KW - Indoor environments Y1 - 2019 U6 - https://doi.org/10.1016/j.gmod.2019.101039 SN - 1524-0703 SN - 1524-0711 VL - 105 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Reimann, Max A1 - Klingbeil, Mandy A1 - Pasewaldt, Sebastian A1 - Semmo, Amir A1 - Trapp, Matthias A1 - Döllner, Jürgen Roland Friedrich T1 - Locally controllable neural style transfer on mobile devices JF - The Visual Computer N2 - Mobile expressive rendering gained increasing popularity among users seeking casual creativity by image stylization and supports the development of mobile artists as a new user group. In particular, neural style transfer has advanced as a core technology to emulate characteristics of manifold artistic styles. However, when it comes to creative expression, the technology still faces inherent limitations in providing low-level controls for localized image stylization. In this work, we first propose a problem characterization of interactive style transfer representing a trade-off between visual quality, run-time performance, and user control. We then present MaeSTrO, a mobile app for orchestration of neural style transfer techniques using iterative, multi-style generative and adaptive neural networks that can be locally controlled by on-screen painting metaphors. At this, we enhance state-of-the-art neural style transfer techniques by mask-based loss terms that can be interactively parameterized by a generalized user interface to facilitate a creative and localized editing process. We report on a usability study and an online survey that demonstrate the ability of our app to transfer styles at improved semantic plausibility. KW - Non-photorealistic rendering KW - Style transfer KW - Neural networks KW - Mobile devices KW - Interactive control KW - Expressive rendering Y1 - 2019 U6 - https://doi.org/10.1007/s00371-019-01654-1 SN - 0178-2789 SN - 1432-2315 VL - 35 IS - 11 SP - 1531 EP - 1547 PB - Springer CY - New York ER - TY - JOUR A1 - Kötzing, Timo A1 - Krejca, Martin Stefan T1 - First-hitting times under drift JF - Theoretical computer science N2 - For the last ten years, almost every theoretical result concerning the expected run time of a randomized search heuristic used drift theory, making it the arguably most important tool in this domain. Its success is due to its ease of use and its powerful result: drift theory allows the user to derive bounds on the expected first-hitting time of a random process by bounding expected local changes of the process - the drift. This is usually far easier than bounding the expected first-hitting time directly. Due to the widespread use of drift theory, it is of utmost importance to have the best drift theorems possible. We improve the fundamental additive, multiplicative, and variable drift theorems by stating them in a form as general as possible and providing examples of why the restrictions we keep are still necessary. Our additive drift theorem for upper bounds only requires the process to be lower-bounded, that is, we remove unnecessary restrictions like a finite, discrete, or bounded state space. As corollaries, the same is true for our upper bounds in the case of variable and multiplicative drift. By bounding the step size of the process, we derive new lower-bounding multiplicative and variable drift theorems. Last, we also state theorems that are applicable when the process has a drift of 0, by using a drift on the variance of the process. KW - First-hitting time KW - Random process KW - Drift Y1 - 2019 U6 - https://doi.org/10.1016/j.tcs.2019.08.021 SN - 0304-3975 SN - 1879-2294 VL - 796 SP - 51 EP - 69 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Friedrich, Tobias A1 - Kötzing, Timo A1 - Krejca, Martin Stefan T1 - Unbiasedness of estimation-of-distribution algorithms JF - Theoretical computer science N2 - In the context of black-box optimization, black-box complexity is used for understanding the inherent difficulty of a given optimization problem. Central to our understanding of nature-inspired search heuristics in this context is the notion of unbiasedness. Specialized black-box complexities have been developed in order to better understand the limitations of these heuristics - especially of (population-based) evolutionary algorithms (EAs). In contrast to this, we focus on a model for algorithms explicitly maintaining a probability distribution over the search space: so-called estimation-of-distribution algorithms (EDAs). We consider the recently introduced n-Bernoulli-lambda-EDA framework, which subsumes, for example, the commonly known EDAs PBIL, UMDA, lambda-MMAS(IB), and cGA. We show that an n-Bernoulli-lambda-EDA is unbiased if and only if its probability distribution satisfies a certain invariance property under isometric automorphisms of [0, 1](n). By restricting how an n-Bernoulli-lambda-EDA can perform an update, in a way common to many examples, we derive conciser characterizations, which are easy to verify. We demonstrate this by showing that our examples above are all unbiased. (C) 2018 Elsevier B.V. All rights reserved. KW - Estimation-of-distribution algorithm KW - Unbiasedness KW - Theory Y1 - 2019 U6 - https://doi.org/10.1016/j.tcs.2018.11.001 SN - 0304-3975 SN - 1879-2294 VL - 785 SP - 46 EP - 59 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Mandal, Sankalita T1 - Event handling in business processes T1 - Ereignisbehandlung in Geschäftsprozessen BT - flexible event subscription for business process enactment BT - flexibles Ereignisabonnement für die Durchführung von Geschäftsprozessen N2 - Business process management (BPM) deals with modeling, executing, monitoring, analyzing, and improving business processes. During execution, the process communicates with its environment to get relevant contextual information represented as events. Recent development of big data and the Internet of Things (IoT) enables sources like smart devices and sensors to generate tons of events which can be filtered, grouped, and composed to trigger and drive business processes. The industry standard Business Process Model and Notation (BPMN) provides several event constructs to capture the interaction possibilities between a process and its environment, e.g., to instantiate a process, to abort an ongoing activity in an exceptional situation, to take decisions based on the information carried by the events, as well as to choose among the alternative paths for further process execution. The specifications of such interactions are termed as event handling. However, in a distributed setup, the event sources are most often unaware of the status of process execution and therefore, an event is produced irrespective of the process being ready to consume it. BPMN semantics does not support such scenarios and thus increases the chance of processes getting delayed or getting in a deadlock by missing out on event occurrences which might still be relevant. The work in this thesis reviews the challenges and shortcomings of integrating real-world events into business processes, especially the subscription management. The basic integration is achieved with an architecture consisting of a process modeler, a process engine, and an event processing platform. Further, points of subscription and unsubscription along the process execution timeline are defined for different BPMN event constructs. Semantic and temporal dependencies among event subscription, event occurrence, event consumption and event unsubscription are considered. To this end, an event buffer with policies for updating the buffer, retrieving the most suitable event for the current process instance, and reusing the event has been discussed that supports issuing of early subscription. The Petri net mapping of the event handling model provides our approach with a translation of semantics from a business process perspective. Two applications based on this formal foundation are presented to support the significance of different event handling configurations on correct process execution and reachability of a process path. Prototype implementations of the approaches show that realizing flexible event handling is feasible with minor extensions of off-the-shelf process engines and event platforms. N2 - Das Prozessmanagement befasst sich mit der Modellierung, Ausführung, Überwachung, Analyse und Verbesserung von Geschäftsprozessen. Während seiner Ausführung kommuniziert der Prozess mit seiner Umgebung, um relevante Kontextinformationen in Form von Ereignissen zu erhalten. Der jüngste Fortschritt im Bereich Big Data und dem Internet der Dinge ermöglicht Smart Devices und Sensoren eine Vielzahl von Ereignissen zu generieren, welche gefiltert, gruppiert und kombiniert werden können, um Geschäftsprozesse zu triggern und vor anzutreiben. Der Industriestandard Business Process Model and Notation (BPMN) stellt mehrere Ereigniskonstrukte bereit, um die Interaktionsmöglichkeiten eines Prozesses mit seiner Umgebung zu erfassen. Beispielsweise können Prozesse durch Ereignisse gestartet, laufende Aktivitäten in Ausnahmefällen abgebrochen, Entscheidungen auf Basis der Ereignisinformationen getroffen, und alternative Ausführungspfade gewählt werden. Die Spezifikation solcher Interaktionen wird als Event Handling bezeichnet. Allerdings sind sich insbesondere in verteilten Systemen die Ereignisquellen des Zustands des Prozesses unbewusst. Daher werden Ereignisse unabhängig davon produziert, ob der Prozess bereit ist sie zu konsumieren. Die BPMN-Semantik sieht solche Situationen jedoch nicht vor, sodass die Möglichkeit besteht, dass das Auftreten von relevanten Ereignissen versäumt wird. Dies kann zu Verzögerungen oder gar Deadlocks in der Prozessauführung führen. Die vorliegende Dissertation untersucht die Mängel und Herausforderungen der Integration von Ereignissen und Geschäftsprozessen, insbesondere in Bezug auf das Subscription Management. Die grundlegende Integration wird durch eine Architektur erreicht, die aus einer Prozessmodellierungskomponente, einer Ausführungskomponente und einer Ereignisverarbeitungskomponente besteht. Ferner werden Points of Subscription and Unsubscription für verschiedene BPMN-Ereigniskonstrukte entlang der Zeitachse der Prozessausführung definiert. Semantische und temporale Abhängigkeiten zwischen der Subscription, dem Auftreten, dem Konsumieren und der Unsubscription eines Ereignisses werden betrachtet. In dieser Hinsicht wird ein Event Bufferdiskutiert, welcher mit Strategien zum Update des Puffers, zum Abruf der geeigneten Ereignisse für den laufenden Prozess, sowie zur Wiederverwendung von Ereignissen ausgestattet ist. Die Abbildung des Event Handling Modells in ein Petri-Netz versieht den beschriebenen Ansatz mit einer eindeutigen Semantik. Basierend auf diesem Formalismus werden zwei Anwendungen demonstriert, die die Relevanz verschiedener Konfigurationen des Event Handlings für eine korrekte Prozessausführung aufzeigen. Eine prototypische Implementierung des Ansatzes beweist dessen Umsetzbarkeit durch geringe Erweiterungen bestehender Software zur Prozessausführung und Ereignisverarbeitung. KW - business process managament KW - complex event processing KW - BPMN KW - event subscription KW - Geschäftsprozessmanagement KW - komplexe Ereignisverarbeitung KW - BPMN KW - Ereignisabonnement Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441700 ER - TY - JOUR A1 - Nikaj, Adriatik A1 - Weske, Mathias A1 - Mendling, Jan T1 - Semi-automatic derivation of RESTful choreographies from business process choreographies JF - Software and systems modeling N2 - Enterprises reach out for collaborations with other organizations in order to offer complex products and services to the market. Such collaboration and coordination between different organizations, for a good share, is facilitated by information technology. The BPMN process choreography is a modeling language for specifying the exchange of information and services between different organizations at the business level. Recently, there is a surging use of the REST architectural style for the provisioning of services on the web, but few systematic engineering approach to design their collaboration. In this paper, we address this gap in a comprehensive way by defining a semi-automatic method for the derivation of RESTful choreographies from process choreographies. The method is based on natural language analysis techniques to derive interactions from the textual information in process choreographies. The proposed method is evaluated in terms of effectiveness resulting in the intervention of a web engineer in only about 10% of all generated RESTful interactions. KW - Business process choreographies KW - RESTful choreographies KW - Natural language analysis Y1 - 2019 U6 - https://doi.org/10.1007/s10270-017-0653-2 SN - 1619-1366 SN - 1619-1374 VL - 18 IS - 2 SP - 1195 EP - 1208 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Schlosser, Rainer A1 - Richly, Keven T1 - Dynamic pricing under competition with data-driven price anticipations and endogenous reference price effects JF - Journal of revenue and pricing management N2 - Online markets have become highly dynamic and competitive. Many sellers use automated data-driven strategies to estimate demand and to update prices frequently. Further, notification services offered by marketplaces allow to continuously track markets and to react to competitors’ price adjustments instantaneously. To derive successful automated repricing strategies is challenging as competitors’ strategies are typically not known. In this paper, we analyze automated repricing strategies with data-driven price anticipations under duopoly competition. In addition, we account for reference price effects in demand, which are affected by the price adjustments of both competitors. We show how to derive optimized self-adaptive pricing strategies that anticipate price reactions of the competitor and take the evolution of the reference price into account. We verify that the results of our adaptive learning strategy tend to optimal solutions, which can be derived for scenarios with full information. Finally, we analyze the case in which our learning strategy is played against itself. We find that our self-adaptive strategies can be used to approximate equilibria in mixed strategies. KW - Dynamic pricing competition KW - Data-driven price anticipation KW - e-Commerce KW - Dynamic programming KW - Response strategies Y1 - 2019 U6 - https://doi.org/10.1057/s41272-019-00206-5 SN - 1476-6930 SN - 1477-657X VL - 18 IS - 6 SP - 451 EP - 464 PB - Palgrave Macmillan CY - Basingstoke ER - TY - JOUR A1 - Pufahl, Luise A1 - Weske, Mathias T1 - Batch activity: enhancing business process modeling and enactment with batch processing JF - Computing N2 - Organizations strive for efficiency in their business processes by process improvement and automation. Business process management (BPM) supports these efforts by capturing business processes in process models serving as blueprint for a number of process instances. In BPM, process instances are typically considered running independently of each other. However, batch processing-the collectively execution of several instances at specific process activities-is a common phenomenon in operational processes to reduce cost or time. Currently, batch processing is organized manually or hard-coded in software. For allowing stakeholders to explicitly represent their batch configurations in process models and their automatic execution, this paper provides a concept for batch activities and describes the corresponding execution semantics. The batch activity concept is evaluated in a two-step approach: a prototypical implementation in an existing BPM System proves its feasibility. Additionally, batch activities are applied to different use cases in a simulated environment. Its application implies cost-savings when a suitable batch configuration is selected. The batch activity concept contributes to practice by allowing the specification of batch work in process models and their automatic execution, and to research by extending the existing process modeling concepts. KW - Batch activity KW - Batch processing KW - Business process models KW - Process Enactment KW - Colored Petri Net Y1 - 2019 U6 - https://doi.org/10.1007/s00607-019-00717-4 SN - 0010-485X SN - 1436-5057 VL - 101 IS - 12 SP - 1909 EP - 1933 PB - Springer CY - Wien ER - TY - JOUR A1 - Bazhenova, Ekaterina A1 - Zerbato, Francesca A1 - Oliboni, Barbara A1 - Weske, Mathias T1 - From BPMN process models to DMN decision models JF - Information systems N2 - The interplay between process and decision models plays a crucial role in business process management, as decisions may be based on running processes and affect process outcomes. Often process models include decisions that are encoded through process control flow structures and data flow elements, thus reducing process model maintainability. The Decision Model and Notation (DMN) was proposed to achieve separation of concerns and to possibly complement the Business Process Model and Notation (BPMN) for designing decisions related to process models. Nevertheless, deriving decision models from process models remains challenging, especially when the same data underlie both process and decision models. In this paper, we explore how and to which extent the data modeled in BPMN processes and used for decision-making may be represented in the corresponding DMN decision models. To this end, we identify a set of patterns that capture possible representations of data in BPMN processes and that can be used to guide the derivation of decision models related to existing process models. Throughout the paper we refer to real-world healthcare processes to show the applicability of the proposed approach. (C) 2019 Elsevier Ltd. All rights reserved. KW - Business process models KW - Decision models KW - BPMN KW - DMN KW - Pattern Y1 - 2019 U6 - https://doi.org/10.1016/j.is.2019.02.001 SN - 0306-4379 SN - 1873-6076 VL - 83 SP - 69 EP - 88 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Risch, Julian A1 - Krestel, Ralf T1 - Domain-specific word embeddings for patent classification JF - Data Technologies and Applications N2 - Purpose Patent offices and other stakeholders in the patent domain need to classify patent applications according to a standardized classification scheme. The purpose of this paper is to examine the novelty of an application it can then be compared to previously granted patents in the same class. Automatic classification would be highly beneficial, because of the large volume of patents and the domain-specific knowledge needed to accomplish this costly manual task. However, a challenge for the automation is patent-specific language use, such as special vocabulary and phrases. Design/methodology/approach To account for this language use, the authors present domain-specific pre-trained word embeddings for the patent domain. The authors train the model on a very large data set of more than 5m patents and evaluate it at the task of patent classification. To this end, the authors propose a deep learning approach based on gated recurrent units for automatic patent classification built on the trained word embeddings. Findings Experiments on a standardized evaluation data set show that the approach increases average precision for patent classification by 17 percent compared to state-of-the-art approaches. In this paper, the authors further investigate the model’s strengths and weaknesses. An extensive error analysis reveals that the learned embeddings indeed mirror patent-specific language use. The imbalanced training data and underrepresented classes are the most difficult remaining challenge. Originality/value The proposed approach fulfills the need for domain-specific word embeddings for downstream tasks in the patent domain, such as patent classification or patent analysis. KW - Deep learning KW - Document classification KW - Word embedding KW - Patents Y1 - 2019 U6 - https://doi.org/10.1108/DTA-01-2019-0002 SN - 2514-9288 SN - 2514-9318 VL - 53 IS - 1 SP - 108 EP - 122 PB - Emerald Group Publishing Limited CY - Bingley ER - TY - JOUR A1 - Möring, Sebastian A1 - de Mutiis, Marco T1 - Camera Ludica BT - Reflections on Photography in Video Games JF - Intermedia games - Games inter media : Video games and intermediality Y1 - 2019 SN - 978-1-5013-3051-3 SN - 978-1-5013-3049-0 SP - 69 EP - 93 PB - Bloomsbury academic CY - New York ER - TY - GEN A1 - Matthies, Christoph T1 - Agile process improvement in retrospectives T2 - 41st International Conference on Software Engineering: Companion Proceedings (ICSE-Companion) N2 - Working in iterations and repeatedly improving team workflows based on collected feedback is fundamental to agile software development processes. Scrum, the most popular agile method, provides dedicated retrospective meetings to reflect on the last development iteration and to decide on process improvement actions. However, agile methods do not prescribe how these improvement actions should be identified, managed or tracked in detail. The approaches to detect and remove problems in software development processes are therefore often based on intuition and prior experiences and perceptions of team members. Previous research in this area has focused on approaches to elicit a team's improvement opportunities as well as measurements regarding the work performed in an iteration, e.g. Scrum burn-down charts. Little research deals with the quality and nature of identified problems or how progress towards removing issues is measured. In this research, we investigate how agile development teams in the professional software industry organize their feedback and process improvement approaches. In particular, we focus on the structure and content of improvement and reflection meetings, i.e. retrospectives, and their outcomes. Researching how the vital mechanism of process improvement is implemented in practice in modern software development leads to a more complete picture of agile process improvement. KW - Agile KW - Scrum KW - software process improvement KW - retrospective Y1 - 2019 SN - 978-1-7281-1764-5 SN - 978-1-7281-1765-2 U6 - https://doi.org/10.1109/ICSE-Companion.2019.00063 SN - 2574-1934 SN - 2574-1926 SP - 150 EP - 152 PB - IEEE CY - New York ER - TY - GEN A1 - Matthies, Christoph T1 - Feedback in Scrum BT - Data-Informed Retrospectives T2 - 2019 IEEE/ACM 41st International Conference on Software Engineering: Companion Proceedings (ICSE-Companion) N2 - Improving the way that teams work together by reflecting and improving the executed process is at the heart of agile processes. The idea of iterative process improvement takes various forms in different agile development methodologies, e.g. Scrum Retrospectives. However, these methods do not prescribe how improvement steps should be conducted in detail. In this research we investigate how agile software teams can use their development data, such as commits or tickets, created during regular development activities, to drive and track process improvement steps. Our previous research focused on data-informed process improvement in the context of student teams, where controlled circumstances and deep domain knowledge allowed creation and usage of specific process measures. Encouraged by positive results in this area, we investigate the process improvement approaches employed in industry teams. Researching how the vital mechanism of process improvement is implemented and how development data is already being used in practice in modern software development leads to a more complete picture of agile process improvement. It is the first step in enabling a data-informed feedback and improvement process, tailored to a team's context and based on the development data of individual teams. KW - agile KW - software development KW - Scrum KW - retrospective KW - software process improvement Y1 - 2019 SN - 978-1-7281-1764-5 SN - 978-1-7281-1765-2 U6 - https://doi.org/10.1109/ICSE-Companion.2019.00081 SN - 2574-1934 SN - 2574-1926 SP - 198 EP - 201 PB - IEEE CY - New York ER - TY - GEN A1 - Brand, Thomas A1 - Giese, Holger T1 - Generic adaptive monitoring based on executed architecture runtime model queries and events T2 - IEEE Xplore N2 - Monitoring is a key functionality for automated decision making as it is performed by self-adaptive systems, too. Effective monitoring provides the relevant information on time. This can be achieved with exhaustive monitoring causing a high overhead consumption of economical and ecological resources. In contrast, our generic adaptive monitoring approach supports effectiveness with increased efficiency. Also, it adapts to changes regarding the information demand and the monitored system without additional configuration and software implementation effort. The approach observes the executions of runtime model queries and processes change events to determine the currently required monitoring configuration. In this paper we explicate different possibilities to use the approach and evaluate their characteristics regarding the phenomenon detection time and the monitoring effort. Our approach allows balancing between those two characteristics. This makes it an interesting option for the monitoring function of self-adaptive systems because for them usually very short-lived phenomena are not relevant. Y1 - 2019 SN - 978-1-7281-2731-6 U6 - https://doi.org/10.1109/SASO.2019.00012 SN - 1949-3673 SP - 17 EP - 22 PB - IEEE CY - New York ER - TY - GEN A1 - Bruechner, Dominik A1 - Renz, Jan A1 - Klingbeil, Mandy T1 - Creating a Framework for User-Centered Development and Improvement of Digital Education T2 - Scale N2 - We investigate how the technology acceptance and learning experience of the digital education platform HPI Schul-Cloud (HPI School Cloud) for German secondary school teachers can be improved by proposing a user-centered research and development framework. We highlight the importance of developing digital learning technologies in a user-centered way to take differences in the requirements of educators and students into account. We suggest applying qualitative and quantitative methods to build a solid understanding of a learning platform's users, their needs, requirements, and their context of use. After concept development and idea generation of features and areas of opportunity based on the user research, we emphasize on the application of a multi-attribute utility analysis decision-making framework to prioritize ideas rationally, taking results of user research into account. Afterward, we recommend applying the principle build-learn-iterate to build prototypes in different resolutions while learning from user tests and improving the selected opportunities. Last but not least, we propose an approach for continuous short- and long-term user experience controlling and monitoring, extending existing web- and learning analytics metrics. KW - learning platform KW - user experience KW - evaluation KW - HPI Schul-Cloud KW - user research framework KW - user-centered design Y1 - 2019 SN - 978-1-4503-6804-9 U6 - https://doi.org/10.1145/3330430.3333644 PB - Association for Computing Machinery CY - New York ER - TY - GEN A1 - Bilo, Davide A1 - Friedrich, Tobias A1 - Lenzner, Pascal A1 - Melnichenko, Anna T1 - Geometric Network Creation Games T2 - SPAA '19: The 31st ACM Symposium on Parallelism in Algorithms and Architectures N2 - Network Creation Games are a well-known approach for explaining and analyzing the structure, quality and dynamics of real-world networks like the Internet and other infrastructure networks which evolved via the interaction of selfish agents without a central authority. In these games selfish agents which correspond to nodes in a network strategically buy incident edges to improve their centrality. However, past research on these games has only considered the creation of networks with unit-weight edges. In practice, e.g. when constructing a fiber-optic network, the choice of which nodes to connect and also the induced price for a link crucially depends on the distance between the involved nodes and such settings can be modeled via edge-weighted graphs. We incorporate arbitrary edge weights by generalizing the well-known model by Fabrikant et al. [PODC'03] to edge-weighted host graphs and focus on the geometric setting where the weights are induced by the distances in some metric space. In stark contrast to the state-of-the-art for the unit-weight version, where the Price of Anarchy is conjectured to be constant and where resolving this is a major open problem, we prove a tight non-constant bound on the Price of Anarchy for the metric version and a slightly weaker upper bound for the non-metric case. Moreover, we analyze the existence of equilibria, the computational hardness and the game dynamics for several natural metrics. The model we propose can be seen as the game-theoretic analogue of a variant of the classical Network Design Problem. Thus, low-cost equilibria of our game correspond to decentralized and stable approximations of the optimum network design. KW - Network creation games KW - edge-weighted networks KW - price of anarchy KW - Nash equilibrium KW - game dynamics KW - computational hardness Y1 - 2019 SN - 978-1-4503-6184-2 U6 - https://doi.org/10.1145/3323165.3323199 SP - 323 EP - 332 PB - Association for Computing Machinery CY - New York ER -