István Koren | Publications

2024

Digital Shadows: Infrastructuring the Internet of Production

van der Aalst, Wil, Jarke, Matthias, Koren, István, and Quix, Christoph

In Internet of Production, 2024. doi:10.1007/978-3-031-44497-5_25

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Abstract Digitization in the field of production is fragmented in very different domains, ranging from materials to production technology to process and business models. Each domain comes with specialized knowledge, often incorporated into mathematical models. This heterogeneity makes it hard to naively exploit advances in data-driven machine learning that could facilitate situation adaptation and experience transfer. Innovative combinations of model-driven and data-driven solutions must be invented but also made comparable and interoperable to avoid ending up in information silos. In future World Wide Labs (WWLs) , experiences can be shared, aggregated, and used for innovation. WWLs will be complex, evolving socio-technical networks of interconnected devices, software, data stores, and humans as users and contributors of expert knowledge and feedback. Integrating a large number of research labs, engineering, and production sites requires a capable cross-domain Internet of Production (IoP) infrastructure. The IoP project claims Digital Shadows (DSs) to offer a shared conceptual foundation for infrastructuring the IoP. In engineering, DSs were introduced as the data provision link to Digital Twins, whereas in computer science, DSs generalize the well-established concept of database views. In this chapter, we elaborate on the roles of DSs in infrastructuring the IoP from three perspectives: analytic functionality, conceptual organization, and technical networking. As an example where an integrative DS-like approach is already highly successful, we showcase the approach and infrastructure of the process mining field.
OCEL (Object-Centric Event Log) 2.0 Specification

Berti, Alessandro, Koren, Istvan, Adams, Jan Niklas, Park, Gyunam, Knopp, Benedikt, Graves, Nina, Rafiei, Majid, Liß, Lukas, Unterberg, Leah Tacke Genannt, Zhang, Yisong, Schwanen, Christopher, Pegoraro, Marco, and van der Aalst, Wil M. P.

In , 2024. doi:10.48550/ARXIV.2403.01975

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Object-Centric Event Logs (OCELs) form the basis for Object-Centric Process Mining (OCPM). OCEL 1.0 was first released in 2020 and triggered the development of a range of OCPM techniques. OCEL 2.0 forms the new, more expressive standard, allowing for more extensive process analyses while remaining in an easily exchangeable format. In contrast to the first OCEL standard, it can depict changes in objects, provide information on object relationships, and qualify these relationships to other objects or specific events. Compared to XES, it is more expressive, less complicated, and better readable. OCEL 2.0 offers three exchange formats: a relational database (SQLite), XML, and JSON format. This OCEL 2.0 specification document provides an introduction to the standard, its metamodel, and its exchange formats, aimed at practitioners and researchers alike.
From Identities to Quantities: Introducing Items and Decoupling Points to Object-Centric Process Mining

Graves, Nina, Koren, István, Rafiei, Majid, and van der Aalst, Wil M. P.

In Process Mining Workshops, 2024. doi:10.1007/978-3-031-56107-8_35

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Adaptive retrofitting for industrial machines: utilizing webassembly and peer-to-peer connectivity on the edge

Nakakaze, Otoya, Koren, István, Brillowski, Florian, and Klamma, Ralf

World Wide Web, 27, 2024. doi:10.1007/s11280-024-01237-8

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Abstract Leveraging previously untapped data sources offers significant potential for value creation in the manufacturing sector. However, asset-heavy shop floors, extended machine replacement cycles, and equipment diversity necessitate considerable investments for achieving smart manufacturing, which can be particularly challenging for small businesses. Retrofitting presents a viable solution, enabling the integration of low-cost sensors and microcontrollers with older machines to collect and transmit data. In this paper, we introduce a concept and a prototype for retrofitting industrial environments using lightweight web technologies at the edge. Our approach employs WebAssembly as a novel bytecode standard, facilitating a consistent development environment from the cloud to the edge by operating on both browsers and bare-metal hardware. By attaining near-native performance and modularity reminiscent of container-based service architectures, we demonstrate the feasibility of our approach. Our prototype was evaluated with an actual industrial robot within a showcase factory, including measurements of data exchange with a cutting-edge data lake system. We further extended the prototype to incorporate a peer-to-peer network that facilitates message routing and WebAssembly software updates. Our technology establishes a foundational framework for the transition towards Industry 4.0. By integrating considerations of sustainability and human factors, it further extends this groundwork to facilitate progression into Industry 5.0.
6th Workshop on Software Engineering for Cyber-Physical Production Systems (SECPPS’24)

Greiner, Sandra, Walter, Jörg, and Koren, István

In , 2024. doi:10.18420/SW2024_57

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OCEL 2.0 Resources – www.ocel-standard.org

Koren, Istvan, Adams, Jan Niklas, and Berti, Alessandro

In , 2024. doi:10.48550/ARXIV.2403.01982

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Process mining has become a cornerstone of process analysis and improvement over the last few years. With the widespread adoption of process mining tools and libraries, the limitations of traditional process mining to deal with event data with multiple case identifiers, i.e., object-centric event data, have become apparent. As a response, the subfield of object-centric process mining has formed, including a file format standardization attempt in the form of OCEL 1.0, unifying the insights of previous developments in capturing object-centric event data. However, discussions among researchers and practitioners have shown that the proposed OCEL 1.0 standard does not go far enough. OCEL 2.0 has been proposed as an advanced refinement, including normative and explicit object-to-object relationships, qualifiers for object-to-object and event-to-object relationships, and evolving object attribute values. This demonstration presents the OCEL 2.0 website available under the URL https://www.ocel-standard.org as a one-stop shop for the detailed specification, example event logs, and broad tool support to facilitate the adoption of the format.

2023

Sustainability and Resilience in Alliance-Driven Manufacturing Ecosystems: A Strategic Conceptual Modeling Perspective

Koren, István, Jarke, Matthias, Piller, Frank T., and Elmaraghy, Hoda

In 56th hawaii international conference on system sciences, HICSS 2023, maui, hawaii, USA, january 3-6, 2023, 2023.
Introduction to the Minitrack on Data Spaces for Sustainability and Resilience in Manufacturing

Jarke, Matthias, Koren, István, Piller, Frank T., and Elmaraghy, Hoda

In 56th hawaii international conference on system sciences, HICSS 2023, maui, hawaii, USA, january 3-6, 2023, 2023.
Engineering Digital Twins and Digital Shadows as Key Enablers for Industry 4.0

Braun, Stefan, Dalibor, Manuela, Jansen, Nico, Jarke, Matthias, Koren, István, Quix, Christoph, Rumpe, Bernhard, Wimmer, Manuel, and Wortmann, Andreas

In Digital Transformation, 2023. doi:10.1007/978-3-662-65004-2_1

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Software in Cyberphysischen Produktionssystemen: Herausforderungen zur Umsetzung in der Industrie

Feichtinger, Kevin, Meixner, Kristof, Rinker, Felix, Koren, István, Eichelberger, Holger, Heinemann, Tonja, Holtmann, Jörg, Konersmann, Marco, Michael, Judith, Neumann, Eva-Maria, Pfeiffer, Jérôme, Rabiser, Rick, Riebisch, Matthias, and Schmid, Klaus

atp magazin, 65, 2023. doi:10.17560/atp.v65i4.2646

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Um den effektiven und effizienten Betrieb von Cyberphysischen Produktionssystemen (CPPSen) sicherzustellen, spielt Software eine zunehmend wichtige Rolle. Die enormen Fortschritte bei Softwareentwicklungsmethoden, welche in den letzten Jahren erzielt wurden, scheinen jedoch die aktuellen Herausforderungen der Industrie nicht zu erfüllen, weil diese die Industrie nicht oder nur langsam erreichen. In diesem Beitrag werden die Herausforderungen für die Softwareentwicklung in CPPSen aus Sicht von neun Industrievertretern aus acht europäischen Unternehmen unterschiedlicher Größe diskutiert. Um den digitalen Transformationsprozess für eine zukunftsfähige Produktion zu begleiten, wurden aus den beschriebenen Herausforderungen Perspektiven für die Forschung erarbeitet. Die Umsetzung dieser Ziele ist vor dem Hintergrund von ökonomischen, sozialen und Nachhaltigkeitsanforderungen notwendig.
Design Elements of a Platform-Based Ecosystem for Industry Applications

Millan, Michael, Becker, Annika, Christou, Ester, Flaig, Roman, Gorißen, Leon, Hinke, Christian, Koren, István, Lohrmann, Vincent, Lüttgens, Dirk, Mertens, Matthias, Wiesch, Marian, Jarke, Matthias, and Piller, Frank

In Internet of Production, 2023. doi:10.1007/978-3-030-98062-7_20-1

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Abstract Many companies in the Industry 4.0 (I4.0) environment are still lacking knowledge and experience of how to enter and participate in a platform-based ecosystem to gain long-term competitive advantages. This leads to uncertainty among firms when transforming into platform-based ecosystems. The article presents a structuralist approach to conceptualize the platform-based ecosystem construct, giving an overview of the literature landscape in a model bundled with unified terminology and different perspectives. The holistic process model aggregates the findings of 130 papers regarding platform-based ecosystem literature. It consists of 4 phases and 16 design elements that unify different terminologies from various research disciplines in one framework and provide a structured and process-oriented approach. Besides, use cases for different design elements were developed to make the model apply in an I4.0 context. Use Case I is a methodology that can be used to model and validate usage hypotheses based on usage data to derive optimization potential from identified deviations from real product usage. By collecting and refining data for analyzing different manufacturing applications and machine tool behavior the importance of specific data is shown in Use Case II and it is highlighted which data can be shared from an external perspective. Use Case III deals with strategic modeling of platform-based ecosystems and the research identifies control points that platform players can actively set to adjust their business models within alliance-driven cooperation to create and capture value jointly. Use Case IV investigates the status quo and expectations regarding platform-based ecosystems in the field of laser technology with the help of structured expert interviews. Overall, this chapter presents a framework on industrial platform-based ecosystems that gives researchers and practitioners a tool and specific examples to get started in this emerging topic.
Challenges and Opportunities of DevOps in Cyber-Physical Production Systems Engineering

Koren, István, Rinker, Felix, Meixner, Kristof, Matevska, Jasminka, and Walter, Jörg

In 2023 IEEE 6th International Conference on Industrial Cyber-Physical Systems (ICPS), 2023. doi:10.1109/ICPS58381.2023.10128073

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GALOIS: A Hybrid and Platform-Agnostic Stream Processing Architecture

Stolz, Tarek, Koren, István, Tirpitz, Liam, and Geisler, Sandra

In Proceedings of the International Workshop on Big Data in Emergent Distributed Environments, 2023. doi:10.1145/3579142.3594287

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Implementing DevOps Practices in CPPS Using Microservices and GitOps

Koren, István, Rinker, Felix, Meixner, Kristof, Kröger, Moritz, and Zeng, Michael

In 2023 IEEE 28th International Conference on Emerging Technologies and Factory Automation (ETFA), 2023. doi:10.1109/ETFA54631.2023.10275433

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Sustainability in the Internet of Production: Interdisciplinary Opportunities and Challenges

Bernhard, Sebastian, Pütz, Sebastian, Röhl, Calvin, Baier, Ralph, Brauner, Philipp, Christou, Ester, Dammers, Hannah, Flaig, Roman, Gorißen, Leon M., Heilinger, Jan-Christoph, Hinke, Christian, Koren, István, Lüttgens, Dirk, Millan, Michael, Müller, Kai, Schollemann, Alexander, Vervier, Luisa, Gries, Thomas, Mertens, Alexander, Nagel, Saskia K., Piller, Frank T., Schuh, Günther, Ziefle, Martina, Nitsch, Verena, and Leicht-Scholten, Carmen

In 2023 IEEE International Symposium on Technology and Society (ISTAS), 2023. doi:10.1109/ISTAS57930.2023.10306192

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Vision Paper: Leveraging Industrial Big Data – Past, Present, and Future of the World Wide Lab

Behery, Mohamed, Glawe, Felix, Koren, István, Ziefle, Martina, Lakemeyer, Gerhard, and Brauner, Philipp

In 2023 IEEE International Conference on Big Data (BigData), 2023. doi:10.1109/BigData59044.2023.10386257

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Actionable Artificial Intelligence for the Future of Production

Behery, Mohamed, Brauner, Philipp, Zhou, Hans Aoyang, Uysal, Merih Seran, Samsonov, Vladimir, Bellgardt, Martin, Brillowski, Florian, Brockhoff, Tobias, Ghahfarokhi, Anahita Farhang, Gleim, Lars, Gorissen, Leon Michel, Grochowski, Marco, Henn, Thomas, Iacomini, Elisa, Kaster, Thomas, Koren, István, Liebenberg, Martin, Reinsch, Leon, Tirpitz, Liam, Trinh, Minh, Posada-Moreno, Andres Felipe, Liehner, Luca, Schemmer, Thomas, Vervier, Luisa, Völker, Marcus, Walderich, Philipp, Zhang, Song, Brecher, Christian, Schmitt, Robert H., Decker, Stefan, Gries, Thomas, Häfner, Constantin Leon, Herty, Michael, Jarke, Matthias, Kowalewski, Stefan, Kuhlen, Torsten W., Schleifenbaum, Johannes Henrich, Trimpe, Sebastian, van der Aalst, Wil M. P., Ziefle, Martina, and Lakemeyer, Gerhard

In Internet of Production, 2023. doi:10.1007/978-3-030-98062-7_4-1

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Abstract The Internet of Production (IoP) promises to be the answer to major challenges facing the Industrial Internet of Things (IIoT) and Industry 4.0. The lack of inter-company communication channels and standards, the need for heightened safety in Human Robot Collaboration (HRC) scenarios, and the opacity of data-driven decision support systems are only a few of the challenges we tackle in this chapter. We outline the communication and data exchange within the World Wide Lab (WWL) and autonomous agents that query the WWL which is built on the Digital Shadows (DS). We categorize our approaches into machine level, process level, and overarching principles. This chapter surveys the interdisciplinary work done in each category, presents different applications of the different approaches, and offers actionable items and guidelines for future work.The machine level handles the robots and machines used for production and their interactions with the human workers. It covers low-level robot control and optimization through gray-box models, task-specific motion planning, and optimization through reinforcement learning. In this level, we also examine quality assurance through nonintrusive real-time quality monitoring, defect recognition, and quality prediction. Work on this level also handles confidence, verification, and validation of re-configurable processes and reactive, modular, transparent process models. The process level handles the product life cycle, interoperability, and analysis and optimization of production processes, which is overall attained by analyzing process data and event logs to detect and eliminate bottlenecks and learn new process models. Moreover, this level presents a communication channel between human workers and processes by extracting and formalizing human knowledge into ontology and providing a decision support by reasoning over this information. Overarching principles present a toolbox of omnipresent approaches for data collection, analysis, augmentation, and management, as well as the visualization and explanation of black-box models.

2022

DevOpsUse: A Community-Oriented Methodology for Societal Software Engineering

Koren, István

In Ernst Denert Award for Software Engineering, 2022. doi:10.1007/978-3-030-83128-8_8

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The demanded fast innovation cycles of the ongoing digital transformation create an unstable environment in which the demands of heterogeneous professional communities need to be addressed. Moreover, the information systems infrastructure of these professional communities has a strong influence on their practices. However, the evolution of the web as infrastructure is shaped by an interplay of new technologies and innovative applications. It is characterized by contrasts, such as centralized versus peer-to-peer architectures, and a large number of end users versus a small number of developers. Therefore, our aim is to stabilize these dichotomies apparent in the web by means of an agile information systems development methodology. The DevOps approach promotes stronger cooperation between development and operations teams. Our DevOpsUse methodology additionally fosters a stronger involvement of end user communities in software development by including them in the process of infrastructuring, i.e. the appropriation of infrastructure during its usage. The developed DevOpsUse methodology and support tools have been successfully validated by the transitions between three generations of technologies: near real-time peer-to-peer web architectures, edge computing, and the Internet of Things. In particular, we were able to demonstrate our methodology’s capabilities through longitudinal studies in several large-scale international digitalization projects. Beyond web information systems, the framework and its open source tools are applicable in further areas like Industry 4.0. Its broad adaptability testifies that DevOpsUse has the potential to unlock capabilities for sustainable innovation.
A Computer Science Perspective on Digital Transformation in Production

Brauner, Philipp, Dalibor, Manuela, Jarke, Matthias, Kunze, Ike, Koren, István (corresponding author), Lakemeyer, Gerhard, Liebenberg, Martin, Michael, Judith, Pennekamp, Jan, Quix, Christoph, Rumpe, Bernhard, van der Aalst, Wil, Wehrle, Klaus, Wortmann, Andreas, and Ziefle, Martina

ACM Transactions on Internet of Things, , 2022. doi:10.1145/3502265

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Review of Commercial and Open Technologies Available for Industrial Internet of Things

Schuh, Günther, Jarke, Matthias, Gützlaff, Andreas, Koren, István, Janke, Tim, and Neumann, Henning

In Design and Operation of Production Networks for Mass Personalization in the Era of Cloud Technology, 2022. doi:10.1016/B978-0-12-823657-4.00005-1

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Internet of Production: Entering Phase Two of Industry 4.0

Kappel, Gertrude, Brecher, Christian, Brockmann, Matthias, and Koren, István

Communications of the ACM, 65, 2022. doi:10.1145/3514093

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Interface Design in Next Generation Manufacturing

Baier, Ralph, Nouduri, Srikanth, Vervier, Luisa, Brauner, Philipp, Koren, István, Ziefle, Martina, and Nitsch, Verena

In Forecasting Next Generation Manufacturing, 2022. doi:10.1007/978-3-031-07734-0_7

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Governance Structures in Next Generation Manufacturing

Brecher, Christian, Jarke, Matthias, Piller, Frank T., Schuh, Günther, Becker, Annika, Brillowski, Florian, Christou, Ester, Koren, István, Kuhn, Maximilian, Lüttgens, Dirk, Van Dyck, Marc, and Wiesch, Marian

In Forecasting Next Generation Manufacturing, 2022. doi:10.1007/978-3-031-07734-0_4

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Industry Voices on Software Engineering Challenges in Cyber-Physical Production Systems Engineering

Feichtinger, Kevin, Meixner, Kristof, Rinker, Felix, Koren, István, Eichelberger, Holger, Heinemann, Tonja, Holtmann, Jörg, Konersmann, Marco, Michael, Judith, Neumann, Eva-Maria, and others,

In Proceedings of the 27th international conference on emerging technologies and factory automation (ETFA), 2022, 2022.
Digital Shadows for Cross-Organizational Data Exchange

Koren, István

In , 2022. doi:10.18420/MODELLIERUNG2022WS-016

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Production settings typically involve heterogeneous systems that create a challenging environment for collecting data in light of digital transformation. Once overcoming these difficulties, data-driven opportunities for manufacturing companies include increasing efficiency and productivity, reducing costs, and improving quality control. On the shop floor, digital shadows and digital twins are elements of these modernization strategies, e.g., to leverage machine learning methods for decision support. Recently, some approaches have transferred these concepts to the organizational level, like digital twins of organizations. In this paper, we envision how we can use data collections from the shop floor, captured as digital shadows, to share data across organizational boundaries to create new business models and ultimately enter new markets. We discuss the necessary enhancements of our conceptual model for digital shadows presented in previous work. We are convinced that digital shadows can help companies embrace innovative, data-driven business models to face challenges like sustainability.
Music Score Analysis with Process Mining

Koren, István

In ICPM doctoral Consortium/Demo, 2022.
Workshop Modeling in (and for) Production

Michael, Judith, and Koren, István

In , 2022. doi:10.18420/MODELLIERUNG2022WS-012

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The production domain is permeated by heterogeneous data sources, a variety of IT systems, and complex industrial use cases - aspects that offer an exciting field for research. The MoPro Workshop aims to be a platform for researchers and practitioners within the production domain to exchange their modeling techniques, interesting use cases, and challenges. We are interested in the use of models for development, production, and usage cycles, as well as model-based and model-driven approaches that span these domains across disciplinary boundaries.
Retrofitting Industrial Machines with WebAssembly on the Edge

Nakakaze, Otoya, Koren, István, Brillowski, Florian, and Klamma, Ralf

In Web Information Systems Engineering – WISE 2022, 2022. doi:10.1007/978-3-031-20891-1_18

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2021

A Standalone WebAssembly Development Environment for the Internet of Things

Koren, István

In Web Engineering, 2021. doi:10.1007/978-3-030-74296-6_27

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Dynamic Strategic Modeling for Alliance-Driven Data Platforms: The Case of Smart Farming

Koren, István, Braun, Stefan, Van Dyck, Marc, and Jarke, Matthias

In Intelligent Information Systems, Advanced Information Systems Engineering - CAiSE Forum 2021, Melbourne, Australia, June 28 - July 22, 2021, Proceedings, 2021. doi:10.1007/978-3-030-79108-7_11

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Mit "Digitalen Schatten" Daten verdichten und darstellen

Jarke, Matthias, van der Aalst, Wil M. P., Brecher, Christian, Brockmann, Matthias, Koren, István, Lakemeyer, Gerhard, Rumpe, Bernhard, Schuh, Günther, Wehrle, Klaus, and Ziefle, Martina

RWTH-Themen, 2, 2021. doi:10.18154/RWTH-2021-02496

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The DFG-funded Excellence Cluster "Internet of Production" envisions a worldwide network of data-sovereign knowledge creation and data sharing in cooperation between engineering and computer science, including also business and social science aspects. This requires the integration of model-based and data-driven AI methods for coherent decision support in the development, operation, and usage cycles of production engineering. The cluster pursues a novel transdisciplinary abstraction called "Digital Shadows" to drive cross-domain research and innovation.
Process Prediction with Digital Twins

Brockhoff, Tobias, Heithoff, Malte, Koren, István, Michael, Judith, Pfeiffer, Jerome, Rumpe, Bernhard, Uysal, Merih Seran, van der Aalst, Wil M. P., and Wortmann, Andreas

In 2021 ACM/IEEE International Conference on Model Driven Engineering Languages and Systems Companion (MODELS-C), 2021. doi:10.1109/MODELS-C53483.2021.00032

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A Conceptual Model for Digital Shadows in Industry and Its Application

Becker, Fabian, Bibow, Pascal, Dalibor, Manuela, Gannouni, Aymen, Hahn, Viviane, Hopmann, Christian, Jarke, Matthias, Koren, István, Kröger, Moritz, Lipp, Johannes, Maibaum, Judith, Michael, Judith, Rumpe, Bernhard, Sapel, Patrick, Schäfer, Niklas, Schmitz, Georg J., Schuh, Günther, and Wortmann, Andreas

In Conceptual Modeling, 2021. doi:10.1007/978-3-030-89022-3_22

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2020

Direwolf Model Academy: An Extensible Collaborative Modeling Framework on the Web

Koren, István, Klamma, Ralf, and Jarke, Matthias

In Companion Proceedings of Modellierung 2020 Short, Workshop and Tools & Demo Papers co-located with Modellierung 2020, Vienna, Austria, February 19-21, 2020.

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Conceptual modeling in Industry 4.0 scenarios enables orchestrating production processes and planning data flows. Since diverse stakeholder groups are involved, collaboration features are particularly important. Common web-based tools are available; however, they focus on either modeling or collaboration. Based on our experiences with these two aspects, we present Direwolf Model Academy, a metamodel framework for creating feature-rich modeling environments on the web. It is based on modern standards like SVG and Web Components; it uses object-oriented programming principles enabled by the latest generation of JavaScript. We already employ tool instances in the areas of user interface generation from service description languages as well as conceptual modeling with iStar 2.0. In this article, we discuss the latter implementation and present the underlying technological foundation. Our framework is available open source on https://github.com/direwolf where we welcome contributions.
A Link Generator for Increasing the Utility of OpenAPI-to-GraphQL Translations

Kus, Dominik, Koren, István, and Klamma, Ralf

In Developers Track, The Web Conference (WWW2020), Virtual, April 20-24,, 2020. doi:10.13140/RG.2.2.33982.92488

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Standardized interfaces are the connecting link of today’s distributed systems, facilitating access to data services in the cloud. REST APIs have been prevalent over the last years, despite several issues like over- and underfetching of resources. GraphQL enjoys rapid adoption, resolving these problems by using statically typed queries. However, the redevelopment of services to the new paradigm is costly. Therefore, several approaches for the successive migration from REST to GraphQL have been proposed, many leveraging OpenAPI service descriptions. In this article, we present the findings of our empirical evaluation on the APIs.guru directory and identify several schema translation challenges. These include less expressive schema types in GraphQL, as well as missing meta information about related resources in OpenAPI. To this end, we developed the open source Link Generator, that analyzes OpenAPI documents and automatically adds links to increase translation utility. This fundamentally benefits around 34% of APIs in the APIs.guru directory. Our findings and tool support contribute to the ongoing discussion about the migration of REST APIs to GraphQL, and provide developers with valuable insights into common pitfalls, to reduce friction during API transformation.
Automatic Bootstrapping of GraphQL Endpoints for RDF Triple Stores

Gleim, Lars, Holzheim, Tim, Koren, István, and Decker, Stefan

In Proceedings of the 4th Workshop on Storing, Querying, and Benchmarking the Web of Data (QuWeDa 2020) at ISWC’20, November 2-3, 2020.

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GraphQL is a query language for graph-structured Web APIs, increasingly popular among Web developers and recently explored as an alternative query language for Linked Data and its underlying RDF data model. However, to date, the deployment of available GraphQL processors for RDF data requires users to have intricate knowledge of Semantic Web technologies, such as SPARQL and SHACL, as well as the schema of the underlying RDF data.We present UltraGraphQL (UGQL), an open source tool enabling the automatic bootstrapping of GraphQL endpoints for existing RDF triple stores, based on an adaptable SPARQL schema extraction, mapping and query translation approach. By automatically generating CRUD mutations for each object type, UGQL further enables write access to RDF data. UGQL thus allows developers with limited or no knowledge of Semantic Web technologies to read and write RDF data using plain GraphQL, eliminating dependencies on third-party schema definitions. By effectively lowering the entry barrier for working with Linked Data, it has the potential to be a ground-breaker for Semantic Web technologies.
An Agricultural Data Platform iStar Model

Braun, Stefan, Koren, István, Van Dyck, Marc, and Jarke, Matthias

In Proceedings of the Thirteenth International iStar Workshop co-located with 28th IEEE International Requirements Engineering Conference (RE 2020), August 31 - September 4, 2020.

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Organizations increasingly rely on external data and service exchange within business networks in order to fuel their analytics and artificial intelligence needs. In Industry 4.0 practices, new ecosystems have evolved, where data and service provisioning often happens within dedicated platforms. Hereby, the challenge lies in ensuring the data sovereignty of enterprises in terms of self-determination with regard to the use of their data. While conceptual modeling of these platforms inhabits a large number of opportunities, for instance, including automated generation of access policies, research in this area is scarce. To this end, we propose a bottom-up approach using the iStar 2.0 modeling language. In this paper, we first introduce a model describing the market participants of a data and service exchange platform in the realm of smart farming. We then generalize and provide a formalization of relevant aspects in a broader context. The resulting models serve both as a basis for discussion on the requirements analysis level and as fundamental groundwork for further value generation in the area of data sovereignty in complex cross-organizational settings.
DevOpsUse: Community-Driven Continuous Innovation of Web Information Infrastructures

Koren, István

PhD Thesis, RWTH Aachen University, 2020. doi:10.18154/RWTH-2020-06868

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Since its invention in 1989, the only reliable factor on the Web has been its continuous change and diffusion into more and more application areas. The evolution was shaped by an interplay of new technologies on the one hand, and innovative application ideas from communities on the other. At a technological scale, alternation between vastly distributed and centralized architectures can be observed. The current challenges caused by the ongoing digital transformation are changing workplace settings and the adoption of the Internet of Things in industrial use cases, as for example in the context of Industry 4.0. On the Web, new technologies and device types sprawl together with new communication protocols and revised application programming interfaces (APIs). This inhibits the demanded rapid innovation cycles and creates a disruptive and unstable environment in which the requirements of endless communities must be met. Information systems infrastructure, while only partially visible and thus hard to grasp, has a strong influence on user practices. Therefore, the aim of this thesis is to stabilize the dichotomies apparent in the Web by means of an agile information systems development methodology. It supports the evolution of infrastructure through community-driven and model-based technologies to guide it on a sustainable path of continuous innovation. Our DevOpsUse methodology includes users in the process of infrastructuring, i.e. the appropriation of infrastructure during its usage. Agile development practices in software engineering, in particular DevOps, promote stronger cooperation between development and operating teams. DevOpsUse additionally fosters a stronger involvement of end users in software development processes. It intends to empower communities of practice to create and run their own software on their specific infrastructure, with the help of various newly developed software artifacts. The instantiation of our DevOpsUse life cycle model starts with Requirements Bazaar, a Web-based tool involving end users in the idea generation and evolution phases. Direwolf is a model-based framework bridging the gap between technocratic API descriptions created by developers, and user interfaces understood by end users. Faster development times require a streamlined deployment, which we achieve with the software container-based Layers Box. Ultimately, distributed development and operation go hand in hand with our evolutionary analytics platform SWEVA. The newly developed DevOpsUse methodology with its four areas, all involving end users, has been successfully validated by the transitions between three generations of technologies: near real-time peer-to-peer Web architectures, edge computing, and the Internet of Things. All technological leaps could be adequately mastered and supported by significantly end-user-oriented measures. In particular, we were able to demonstrate our methodology’s capabilities through longitudinal studies in several large-scale international digitalization projects. DevOpsUse scalability and involvement aspects were confirmed in entrepreneurial and medical teaching courses. Beyond Web information systems, the framework and its open source tools are applicable in further innovative areas like mixed reality and Industry 4.0. Its broad adaptability testifies that DevOpsUse has the potential to unlock sustainable innovation capabilities.

2019

Infrastructuring for Crowdsourced Co-Design

Bonilla Oliva, Delcy Carolina, Koren, István, and Klamma, Ralf

Interaction Design and Architecture (IxD&A), 42, 2019.

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User satisfaction determines the quality of a product idea. Yet it is hard to accomplish when designers are isolated from their users, creating a gap in the design practices. Co-design seeks to meet the needs of users by giving them a voice in the design process. Technology-enhanced learning provides an ideal testbed, as co-design practices on learning content are well-established between instructors, e.g. in instructional design. The challenges are first to convene geographically distributed users to collaborate on design of software applications and second to scale up to a high number of users. We present Pharos, a platform where designers can request feedback from a community of people with different backgrounds. It combines co-design with crowdsourcing to enable mass feedback. A user evaluation showed that designers preferred structured feedback from a crowd of users rather than open-ended critique from co-designers. Based on the evaluation, we discuss possible improvements of Pharos and motivate further studies. The resulting Web application is available as open source software.
Immersive Community Analytics for Wearable Enhanced Learning

Klamma, Ralf, Ali, Rizwan, and Koren, István

In Learning and Collaboration Technologies. Ubiquitous and Virtual Environments for Learning and Collaboration, 2019.

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Nowadays, we can use immersive interaction and display technologies in collaborative analytical reasoning and decision making scenarios. In order to support heterogeneous professional communities of practice in their digital transformation, it is necessary not only to provide the technologies but to understand the work practices under transformations as well as the security, privacy and other concerns of the communities. Our approach is a comprehensive and evolutionary socio-technological learning analytics and design process leading to a flexible infrastructure where professional communities can co-create their wearable enhanced learning solution. In the core, we present a multi-sensory fusion recorder and player that allows the recordings of multi-actor activity sequences by human activity recognition and the computational support of immersive learning analytics to support training scenarios. Our approach enables cross-domain collaboration by fusing, aggregating and visualizing sensor data coming from wearables and modern production systems. The software is open source and based on the outcomes of several national and international funded projects.
OakStreaming: A Peer-to-PeerVideo Streaming Library

Koren, István, and Klamma, Ralf

Journal of Web Engineering, 17, 2019. doi:10.13052/jwe1540-9589.17675

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Multimedia platforms dealing with movie streaming and video-based short messages have increased the global Internet video traffic substantially in the last couple of years. Over the same period, multimedia on the Web has been standardized in terms of codecs and browser-based JavaScript APIs. However, today the technological challenges concerning the distribution of large video files are mainly tackled by scaling up capacities in cloud data centers, or relying on content delivery networks. Both approaches favor financially strong, large companies, while independent video providers with highly demanded videos are disadvantaged. Peer-to-peer streaming provides an alternative by shifting the data streams to the clients. In this article, we conceptualize different methods to move video delivery from centralized cloud infrastructures to end user devices. We discuss their strengths & weaknesses and present design considerations. To exemplify a particular approach, we showcase the implementation and evaluation of OakStreaming, our system that streams videos peer-to-peer via WebTorrent in HTML5. Particularly, we offer Web video providers a library that has various parameters, for instance to limit the bandwidth available for peer-to-peer uploads. The resulting library is available as open source software on GitHub.

2018

An Augmented Reality Framework for Gamified Learning

Hensen, Benedikt, Koren, István, Klamma, Ralf, and Herrler, Andreas

In Advances in Web-Based Learning – ICWL 2018, Proceedings of the 17th International Conference, Chiang Mai, Thailand, August 22-24, 2018. doi:10.1007/978-3-319-96565-9_7

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Formal education with physical objects is resource-intensive and does not scale well. In self-regulated settings, the long-term motivation of learners is an additional issue. Interactive 3D models provide a solution, as they can be replicated as needed. The user experience and immersiveness suffers in conventional Web-based viewers. The concept of mixed reality which encompasses both virtual and augmented reality creates new opportunities. In this article, we present a framework for mixed reality training that allows students to experience 3D models in an augmented reality environment. The resulting app runs on the Microsoft HoloLens and is suited for several settings like bedside teaching and workplace learning. User motivation and learning success are supported by a gamification strategy that rewards the successful completion of quizzes. We evaluated our framework with students of a medical university. Our open source software can be readily employed in various academic and industrial application areas.
Augmented Reality Lernkontexte – Eine Europäische Perspektive

Koren, István, Hensen, Benedikt, and Klamma, Ralf

In Proceedings der Pre-Conference-Workshops der 16. E-Learning Fachtagung Informatik, Frankfurt am Main, Germany, September 10, 2018.

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Augmented Reality (AR) ist auf dem Weg, sich in der Wirtschaft und der Lehre zu etablieren. In den letzten Jahren sind durch Forschung und Entwicklung viele neue Technologien, Methoden und Softwareentwicklungswerkzeuge auf den Markt gekommen. Allerdings fehlen sowohl in der Erstellung von Lehrmaterialien, als auch in der Nutzung von AR in der Lehre einheitliche Richtlinien oder gar Standards. Darüber hinaus müssen in der Wirtschaft genügend gut ausgebildete Fachkräfte vorhanden sein, welche die aufgestellten AR-Konzepte umsetzen können, so dass ein Transfer aus der Hochschule in die Wirtschaft notwendig ist. Daher gehen wir in diesem Beitrag sowohl auf Herausforderungen im Lernen mit AR, als auch auf die speziellen Bedürfnisse des Lernens über AR ein. Wir nehmen dazu als Informatiker eine europäische, interdisziplinäre und anwendungsnahe Perspektive ein, da unsere Erfahrungen aus mehreren geförderten europäischen Projekten in diesen Bereichen stammen. Dabei versuchen wir auch, neue Impulse in Lehrkontexten in unserem Rahmenwerk aufzunehmen, wie Gamifizierung, Learning Analytics und Experience Capturing. Zusätzlich weisen wir auf Standardisierungsbemühungen wie IEEE ARLEM hin. Die konzeptuellen und technischen Lösungsansätze stellen wir als Open Content und Open Source zur Verfügung, um einer möglichst schnellen Verbreitung Vorschub zu leisten. Aus diesem Grund laden alle unsere Aktivitäten explizit zur aktiven Teilnahme ein.
Co-Design of Gamified Mixed Reality Applications

Koren, István, Hensen, Benedikt, and Klamma, Ralf

In Proceedings of the IEEE ISMAR 2018 Workshop on Creativity in Design with & for Mixed Reality, Munich, Germany, October 20, 2018. doi:10.1109/ISMAR-Adjunct.2018.00094

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Mixed reality applications currently make their way into diverse academic and industrial domains. Due to the evolving character of this new technology, early adopters face a variety of challenges for example in soft- and hardware availability. Another deficit is the lack of content. Opening up the production life cycle to involve users early on can help to improve the acceptance and target new possibilities. In this article we present a methodology and tool support for co-designing mixed reality applications by combining requirements engineering and gamification. This enables both creating a continuous innovation life cycle and achieving long-term motivation. Our prototype was evaluated in the context of technology-enhanced learning at a medical school. We are confident that our results are transferable to other application areas, as all our components are freely available as open source resources.
Enabling visual community learning analytics with Internet of Things devices

Koren, István, and Klamma, Ralf

Computers in Human Behavior, 89, 2018. doi:10.1016/j.chb.2018.07.036

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Industry 4.0 is currently transforming industrial workplaces into sensor-assisted high-tech environments. While it is often feared that jobs will be lost through increasing automation, we are convinced that there is an enormous potential for versatile and competent workers at innovative workplaces. Training at the workplace may contribute to this. In this context, both body-near wearables and industrial devices produce an enormous amount of data. However, the question is how to deal with this amount of data. To this end, visual analytics is a combination of computational techniques from data mining and machine learning with human perceptional methods from human-computer interaction. In this article we present a method and tool support to create rich and interactive visual analytics charts to analyze innovative training solutions in high-tech workplace settings. This brings together the computer’s capacities to handle large data and calculation resources with the human ability to quickly grasp relationships. Our technical evaluation shows, that the approach is feasible from a computational perspective; usability tests revealed that the developed pipeline metaphor reaches its goal. Our results may help in designing future systems that fulfill the needs of both trainers and learners in Industry 4.0 settings.
Generation of Web Frontends from API Documentation with Direwolf Interaction Flow Designer

Koren, István, and Klamma, Ralf

In Proceedings of the 18th International Conference on Web Engineering, ICWE 2018, Cáceres, Spain, June 5-8, 2018. doi:10.1007/978-3-319-91662-0_42

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Services and their interfaces are a cornerstone of Web applications. API description formats help developers in accessing and combining service functionalities. The OpenAPI specification has gained considerable popularity over the last years. Existing tools around OpenAPI support the generation of HTML interfaces to mockup requests. While these interfaces are suited well for developers, it remains hard for non-developers to assess service functionalities. To this end, we present the Direwolf Interaction Flow Designer in this demo. It parses OpenAPI documents to generate Web frontends with the help of the Interaction Flow Modeling Language (IFML). A screencast of our tool is available online at https://youtu.be/KFOPmPShak4 .
Peer-to-Peer Video Streaming in HTML5 with WebTorrent

Koren, István, and Klamma, Ralf

In Web Engineering, Proceedings of the 18th International Conference, ICWE 2018, Cáceres, Spain, June 5-8, 2018. doi:10.1007/978-3-319-91662-0_33

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Multimedia-related businesses dealing with movie streaming and video-based short messages have increased the global Internet video traffic substantially in the last couple of years. At the same time, multimedia on the Web has been standardized in terms of codecs and browser-based JavaScript APIs. However, the technological challenges concerning the distribution of large video files are today mainly tackled by scaling up capacities in cloud data centers, or relying on content delivery networks. Both approaches favor financially strong, large companies, while independent video providers with highly demanded videos are disadvantaged. In this article, we conceptualize methods to offload video delivery from centralized clouds to clients. In particular, we implemented and evaluated a system that streams videos peer-to-peer via WebTorrent in HTML5. The resulting library is available open source.
The Exploitation of OpenAPI Documentation for the Generation of Web Frontends

Koren, István, and Klamma, Ralf

In Companion Proceedings of the The Web Conference 2018 on The Web Conference 2018 - WWW ’18, Lyon, France, April 23-27, 2018. doi:10.1145/3184558.3188740

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New Internet-enabled devices and Web services are introduced on a daily basis. Documentation formats are available that describe their functionalities in terms of API endpoints and parameters. In particular, the OpenAPI specification has gained considerable influence over the last years. Web-based solutions exist that generate interactive OpenAPI documentation with HTML5 & JavaScript. They allow developers to quickly get an understanding what the services and devices do and how they work. However, the generated user interfaces are far from real-world practices of designers and end users. We present an approach to overcome this gap, by using a model-driven methodology resulting in state-of-the-art responsive Web user interfaces. To this end, we use the Interaction Flow Modeling Language (IFML) as intermediary model specification to bring together APIs and frontends. Our implementation is based on open standards like Web Components and SVG. A screencast of our tool is available at https://youtu.be/KFOPmPShak4
Joint Proceedings of the 1st Co-Creation in the Design, Development and Implementation of Technology-Enhanced Learning workshop (CC-TEL 2018) and Systems of Assessments for Computational Thinking Learning workshop (TACKLE 2018), Leeds, United Kingdom, September 3, 2018

Piotrkowicz, Alicja, Dent-Spargo, Rosie, Dennerlein, Sebastian, Koren, István, Antoniou, Panagiotis, Bailey, Paul, Treasure-Jones, Tamsin, Fronza, Ilenia, and Pahl, Claus

2018.

URL

2017

Community Learning Analytics with Industry 4.0 and Wearable Sensor Data

Koren, István, and Klamma, Ralf

In Immersive Learning Research Network, Proceedings of the Third International Conference, iLRN 2017, Coimbra, Portugal, June 26–29, 2017. doi:10.1007/978-3-319-60633-0_12

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Learning analytics in formal learning contexts is often restricted to collect and analyze data from students following curricula through a learning management system. In informal learning, however, a deep understanding of learners and entities interacting with each other is needed. The practice of exploring these interactions is known as community learning analytics. Mobile devices, wearables and interconnected Industry 4.0 production machines equipped with a multitude of sensors collecting vast amounts of data are ideal candidates to capture the goals and activities of informal learning settings. What is missing is a methodological approach to collect, manage, analyze and exploit data coming from such an interconnected network of artifacts. In this paper, we present a concept and prototypical implementation of a framework that is able to gather, transform and visualize data coming from Industry 4.0 and wearable sensors and actuators. Our collaborative Web-based visual analytics platform is highly embeddable and extensible on various levels. Its open source availability fosters research on community learning analytics on a broad level.
Preparing Research Projects for Sustainable Software Engineering in Society

Renzel, Dominik, Koren, István, Klamma, Ralf, and Jarke, Matthias

In Proceedings of the 2017 IEEE/ACM 39th IEEE International Conference on Software Engineering (ICSE), Buenos Aires, Argentina, May 20-28, 2017. doi:10.1109/ICSE-SEIS.2017.4

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With the pervasive need for digitization in mod- ern information society, publicly funded research projects in- creasingly focus on engineering digital approaches to manage societal processes. Such projects inherently face the challenge of establishing a sustainable software engineering culture. A major challenge thereby is that project consortia need to establish a distributed developer community that effectively and resource- efficiently aligns development efforts with the goals and needs of complex societal constellations beyond project lifetime. In this paper we extract empirical evidence from longitudinal studies in two large-scale research projects to outline typical challenges in such problem contexts and to develop an open source soft- ware engineering methodology for research projects, including supportive infrastructure and social instruments of community building and awareness. We thus contribute a comprehensive strategy preparing collaborative research projects for sustainable societal software engineering.

2016

Smart Ambient Learning with Physical Artifacts Using Wearable Technologies

Koren, István, and Klamma, Ralf

EAI Endorsed Transactions on Future Intelligent Educational Environments, 2, 2016. doi:10.4108/eai.27-6-2016.151526

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Wearable technologies have been developing a momentum recently. However, integrated concepts for teaching and learning with wearable technologies are not available at present. In this paper, we report on a multicontextual framework for such an integrated concept. It consists of a number of real-world use cases coming from a third-party funded project, an entrepreneurship lab course from a technical university and an open source software development strategy. Based on an exhibition scenario, we conceptualize a framework for dealing with physical artifacts that integrates community learning analytics for self-reflection. Conceptual as well as technical issues and first experiences with an open source prototype draw an optimistic picture while we outline further needs for research and development.
The Direwolf Inside You: End User Development for Heterogeneous Web of Things Appliances

Koren, István, and Klamma, Ralf

In Web Engineering, Proceedings of the 16th International Conference, ICWE 2016, Lugano, Switzerland, June 6-9, 2016. doi:10.1007/978-3-319-38791-8_35

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Mobile computing devices like smartphones have become a commodity. They are very convenient when connecting to ubiquitous Web of Things (WoT) appliances. However, WoT manufacturers are challenged to provide Web application interfaces for a multitude of mobile platforms in a short time. Moreover, end users are required to install dedicated Web apps for giving them access to these emerging technologies. To overcome this situational overburdening efforts, end user development in the form of component-based Web mashups has already been applied successfully in various domains. In this paper, we envision a framework for letting users create situational applications for opportunistic device usage. We explore the recent Web Component group of W3C recommendations as a foundation for peer-to-peer cross-platform, cross-application and cross-user Web applications. Our preliminary experiences may help the Web engineering community to build better Web infrastructures for a heterogeneous device landscape.
DevOpsUse for Rapid Training of Agile Practices Within Undergraduate and Startup Communities

de Lange, Peter, Nicolaescu, Petru, Klamma, Ralf, and Koren, István

In Adaptive and Adaptable Learning, Proceedings of the 11th European Conference on Technology Enhanced Learning (EC-TEL 2016), Lyon, France, September 13-16, 2016. doi:10.1007/978-3-319-45153-4_65

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Establishing a common practice between (startup) companies and universities in applied computer science labs has been tackled by pedagogical approaches based on the communities of practice theory. However, modern agile and distributed software engineering methods and recent developments like DevOps demand focused training of undergraduate students to enable them joining practices in companies. In this paper, we present the Community Application Editor (CAE) embedded in a DevOpsUse methodology supporting this form of basic training for bachelor students of computer science. We have evaluated the methodology and the tool usage in a first-stage undergraduate lab course. The results indicate that the students had a much smoother transition when later joining the second-stage lab with real companies.

2015

Distributed Software Engineering in Collaborative Research Projects

Derntl, Michael, Renzel, Dominik, Nicolaescu, Petru, Koren, István, and Klamma, Ralf

In Proceedings of the 2015 IEEE 10th International Conference on Global Software Engineering (ICGSE 2015), Ciudad Real, Spain, July 13-16, 2015. doi:10.1109/ICGSE.2015.12

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Collaborative research projects involve distributed construction of software prototypes as part of the project methodology. A major challenge thereby is the need to establish a developer community that shall effectively and efficiently align development efforts with requirements offered by researchers and other stakeholders. These projects are inherently different in nature compared to commercial software projects. The literature offers little research on this aspect of software engineering. In this paper, we outline the challenges in this context and present a methodology for distributed software engineering in collaborative research projects. The methodology covers all major aspects of the software engineering process including requirements engineering, architecture, issue tracking, and social aspects of developer community building in collaborative projects. The methodology can be tailored to different project contexts and may provide support in planning software engineering work in future projects.
Collaborative Drawing Annotations on Web Videos

Koren, István, Nicolaescu, Petru, and Klamma, Ralf

In Engineering the Web in the Big Data Era, Proceedings of the 15th International Conference on Web Engineering (ICWE 2015), Rotterdam, Netherlands, June 23-26, 2015. doi:10.1007/978-3-319-19890-3_54

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Collaborative Drawing over a computer network, in particular on videos, usually requires some complex client-server architecture. In this paper, we want to demo an approach with the following distinctive features. On the client side we enable peer-to-peer collaborative video drawing in recent Web browsers supporting WebRTC. Developers can therefore embed it in arbitrary Web pages and users do not need to install any additional software. For persistence we use a microservice driven cloud approach which can be set up easily. All components are open source to facilitate wide use and further development. A use case evaluation showed promising results and will be presented in the demo.
Smart Ambient Learning with Physical Artifacts Using Wearable Technologies

Koren, István, and Klamma, Ralf

In Workshop Proceedings of the 11th International Conference on Intelligent Environments, Prague, Czech Republic, July 15-17, 2015. doi:10.3233/978-1-61499-530-2-325

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Wearable technologies have been developing a momentum recently. However, integrated concepts for teaching and learning with wearable technologies are still not existing in the moment. In this paper, we report about a multi-contextual framework for such an integrated concept. It consists of a number of real-world use-cases coming from a third-party funded project, an entrepreneurial teaching course from a technical university and an open source software development strategy. Conceptual as well as technical issues and first experiences draw an optimistic picture while we outline further needs in research and development.

2014

Blueprint for Software Engineering in Technology Enhanced Learning Projects

Derntl, Michael, Koren, István, Nicolaescu, Petru, Renzel, Dominik, and Klamma, Ralf

In Open Learning and Teaching in Educational Communities, Proceedings of the 9th European Conference on Technology Enhanced Learning (EC-TEL 2014), Graz, Austria, September 16-19, 2014. doi:10.1007/978-3-319-11200-8_33

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Many projects in Technology Enhanced Learning (TEL) aim to develop novel approaches, models, and systems by field-testing new ideas with software prototypes. A major challenge is that project consortia need to establish a distributed, typically understaffed developer community that has to align its development efforts with needs from application partners and input from research partners. Tackling this challenge, this paper provides a blueprint for software engineering process and infrastructure, which was distilled from successful practices in recent TEL projects. We present a composition of freely available instruments that support open, distributed software engineering practices using continuous integration processes. The blueprint considers the full development cycle including requirements engineering, software architecture, issue tracking, build management and social aspects of developer community building in TEL projects. Some lessons learned are provided, particularly related to open source commitment, innovation as a social process, and the essential role of time. We aim to make software development in TEL fit for Horizon 2020 with processes and instruments that can be readily adopted for planning and executing future projects.
DireWolf Goes Pack Hunting: A Peer-to-Peer Approach for Secure Low Latency Widget Distribution Using WebRTC

Koren, István, Bavendiek, Jens, and Klamma, Ralf

In Web Engineering, Proceedings of the 14th International Conference on Web Engineering (ICWE 2014), Toulouse, France, July 1-4, 2014. doi:10.1007/978-3-319-08245-5_38

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Widget-based Web applications are outperforming monolithic Web applications in terms of distribution of the user interface on many devices and many standard browsers. However, latency of the remote inter-widget communication may be an obstacle for the uptake of Widget-based Web applications in near real-time domains like Web gaming and augmented reality. In this demo paper we show DireWolf 2.0 which is replacing the XMPP server of the DireWolf approach by a client-side relay realized by the means of WebRTC. This is not only decreasing the latency of the distributed interface for any application but also increasing the security by avoiding man-in-the-middle attacks on the XMPP server. This progress is enabling further uptake in Widget-based solutions in advanced Web engineering.
Turning User Requirements Into Technical Features With the House of Quality

Koren, István

In Large-Scale Social Requirements Engineering, IEEE Special Technical Community on Social Networking (IEEE STCSN) E-Letter, 2014.

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Requirements Bazaar is a Web based tool for Large-Scale Social Requirements Engineering (LASSRE) which outputs a list of requirements weighted by user votes. However these user demands are often hard to relate to concrete technical system parts. In this short tutorial we show how this relation may be established by using the methodology called Quality Function Deployment (QFD) and especially its instantiation, the House of Quality, to help transforming user requirements into a software product.
DireWolf: A Framework for Widget-based Distributed User Interfaces

Kovachev, Dejan, Renzel, Dominik, Nicolaescu, Petru, Koren, István, and Klamma, Ralf

Journal of Web Engineering, 13, 2014.

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Web applications have overcome traditional desktop applications especially in collaborative settings. However, the bulk of Web applications still follow the \textquotedblsingle user on a single device\textquotedbl computing model. Therefore, we created the DireWolf framework for rich Web applications with distributed user interfaces (DUIs) over a federation of heterogeneous commodity devices supporting modern Web browsers such as laptops, smart phones and tablet computers. The DUIs are based on widget technology coupled with cross-platform inter-widget communication (IWC) and seamless session mobility. Inter-widget communication technologies connect the widgets and enable real-time collaborative applications as well as runtime migration in our framework. We show that the DireWolf framework facilitates the use case of DUI-enabled semantic video annotation. For a single user it provides more flexible control over different parts of an application by enabling the simultaneous use of smart phones, tablets and computers. We conducted a technical evaluation and two user studies to validate the DireWolf approach. The work presented opens the way for creating distributed Web applications which can access device specific functionalities such as multi-touch, text input, etc. in a federated and usable manner. In this paper, we also sketch our ongoing work to integrate the WebRTC API into DireWolf, where we see opportunities for potential adoption of DUI Web applications by the majority of Web users.
A Community Information System for Ubiquitous Informal Learning Support

Nicolaescu, Petru, Renzel, Dominik, Koren, István, Klamma, Ralf, Purma, Jukka, and Bauters, Merja

In 2014 IEEE 14th International Conference on Advanced Learning Technologies (ICALT 2014), Athens, Greece, July 7-10, 2014. doi:10.1109/ICALT.2014.48

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There are many mobile apps supporting informal learning tasks like sense-making out of multimedia materials. However, regardless how well these have been implemented, their scope and scalability is limited either by over-specialization and consequently limited transferability or by over-generalization - with a lack of informal learning support for most Web 2.0 apps. Our cloud-based mobile Web information system approach is theoretically founded and designed for scalability in informal learning. As a proof of concept we present a semantic video annotation scenario for supporting informal learning at workplace. As the approach has been designed for community learning analytics, we can present results from a preliminary evaluation. We conducted our research with a strong commitment towards open source software development, so that our solutions are already available and can have impact beyond the usual scope of a funded project.
Global-Scale Federated Access to Smart Objects Using XMPP

Schuster, Daniel, Grubitzsch, Philipp, Renzel, Dominik, Koren, István, Klauck, Ronny, and Kirsche, Michael

In Proceedings 2014 IEEE International Conference on Internet of Things (iThings 2014), Green Computing and Communications (GreenCom 2014), and Cyber-Physical-Social Computing (CPSCom 2014), Taipei, Taiwan, September 1-3, 2014. doi:10.1109/iThings.2014.35

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Communication with smart objects currently only works in isolated, sometimes even proprietary islands. This lack of interoperability limits the value of smart objects connected to the Internet of Things (IoT). We propose to use the eXtensible Messaging and Presence Protocol (XMPP) to connect IoT islands. XMPP is inherently federated, secure, globally scalable and designed for collaboration. We use XMPP Multi-User Chat (MUC) to build a secure and accessible platform for sensor data exchange between organizations. We demonstrate a scenario of three distributed and interconnected XMPP-driven sites, whereas different client types access sensor data from all sites. Our evaluation results confirm that the architectural pattern presented in this work can easily be used in any XMPP-based system without the need to enhance or to extend the standards.

2013

Shared Editing on the Web: A Classification of Developer Support Libraries

Koren, István, Guth, Andreas, and Klamma, Ralf

In Proceedings of the 9th IEEE International Conference on Collaborative Computing: Networking, Applications and Worksharing (Collaboratecom 2013), Austin, Texas, USA, October 20-23, 2013. doi:10.4108/icst.collaboratecom.2013.254097

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Together with the current shift to cloud-based solutions, various Web applications have been enriched with collaborative features. These collaborative features enable users to work together on digital products like documents, diagrams and videos at the same time on a global scale. Implementing them require developers to have knowledge about both complex algorithms for maintaining consistency on one hand and usability issues on the other hand. Besides developing apps from scratch, Web application developers often meet these challenges by employing ready-made libraries for shared editing on the Web. A new generation of these shared editing frameworks has emerged recently; several of these libraries are available as open source solutions. In this paper, we first present general and browser-specific requirements for shared editing like consistency algorithms and means of workspace awareness. Then, state-of-the-art frameworks for shared editing are analyzed in respect of their support of these requirements. As a contribution, we have identified missing features like the availability of general awareness widgets and new architectural designs due to emerging Web standards. To that end, we demonstrate prototypes addressing some of these issues.
Session Mobility for Collaborative Pervasive Apps Using XMPP

Koren, István, Schuster, Daniel, and Springer, Thomas

In 2013 IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops), San Diego, California, USA, March 18-22, 2013. doi:10.1109/PerComW.2013.6529476

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In pervasive computing scenarios, user sessions often involve multiple devices like smartphones, tablets, large public displays and smart objects. In such settings, session mobility allows users to split sessions across several devices, to dynamically include or remove devices from sessions and to handover sessions from one device to another. While there are some good SIP-based solutions for session mobility in ubiquitous audio/video scenarios, there is yet no working approach for collaborative apps with event-like communication patterns. We describe and evaluate a solution for session mobility based on XMPP offering discovery of personal devices, discovery and authorization of public devices, and ad-hoc discovery of smart objects. All this can be done with little or no modification of existing XMPP technology, thus creating a standard-based toolset for session mobility. This eases development of collaborative apps and finally allows users to seamlessly continue their task in pervasive settings.

2012

Creating Applications for Real-Time Collaboration with XMPP and Android on Mobile Devices

Schuster, Daniel, Koren, István, Springer, Thomas, Hering, Dirk, Söllner, Benjamin, Endler, Markus, and Schill, Alexander

In Handbook of Research on Mobile Software Engineering: Design; Implementation and Emergent Applications, 2012. doi:10.4018/978-1-61520-655-1.ch045

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The goal of this chapter is to discuss the challenges of generic protocols and platforms for mobile collaboration in general and for the adoption of XMPP for mobile collaboration in particular. The chapter will introduce the XMPP protocol family, discuss its potentials and issues for mobile collaboration, and describe experiences with the implementation of mobile collaborative middleware and applications based on XMPP. In particular the protocol family has been used to create a generic middleware for mobile collaboration providing a set of generic services such as publish/subscribe, group management, and chat functionality, as well as advanced functionality for geo-location and geo-tagging, map visualization, and multimedia content sharing. For the implementation of our platform and applications XMPP is used in combination with the Android platform running on the mobile devices. The authors describe their experiences in adjusting and adopting XMPP protocol implementations based on Java on the Android platform.