István Koren

Collaborative Drawing Annotations on Web Videos

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.

The Direwolf Inside You: End User Development for Heterogeneous Web of Things Appliances

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.

Global-Scale Federated Access to Smart Objects Using XMPP

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.

Preparing research projects for sustainable software engineering in society

With the pervasive need for digitization in modern information society, publicly funded research projects increasingly 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 software 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.

DevOpsUse for Rapid Training of Agile Practices Within Undergraduate and Startup Communities

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.

Smart Ambient Learning with Physical Artifacts Using Wearable Technologies

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. Received on 4 December 2015; accepted on 23 February 2016; published on 27 June 2016

DireWolf Goes Pack Hunting: A Peer-to-Peer Approach for Secure Low Latency Widget Distribution Using WebRTC

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.

An Augmented Reality Framework for Gamified Learning

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.

Generation of Web Frontends from API Documentation with Direwolf Interaction Flow Designer

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 (https://youtu.be/KFOPmPShak4).

Peer-to-Peer Video Streaming in HTML5 with WebTorrent.

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.