Christian Willems

Tele-Board: Enabling efficient collaboration in digital design spaces

Remote collaboration among geographically dispersed team members has become standard practice for many companies and research teams. A number of computer supported collaborative work systems exist, but there still lacks acceptable support for teams working in creative settings, where traditionally numerous physical and analog tools are used. We have created an environment for teams applying creative methods that allows them to work together efficiently across distances, without having to change their working modes. We present the Tele-Board system, which combines video conferencing with a synchronous transparent whiteboard overlay. This setup enables regionally separated team members to simultaneously manipulate artifacts while seeing each others gestures and facial expressions. Our systems flexible architecture maximizes hardware independence by supporting a diverse selection of input devices.

The Service Security Lab: A Model-Driven Platform to Compose and Explore Service Security in the Cloud

Cloud computing enables the provisioning of dynamically scalable resources as a service. Next to cloud computing, the paradigm of Service-oriented Architectures emerged to facilitate the provisioning of functionality as services. While both concepts are complementary, their combination enables the flexible provisioning and consumption of independently scalable services. These approaches come along with new security risks that require the usage of identity and access management solutions and information protection. The requirements concerning security mechanisms, protocols and options are stated in security policies that configure the interaction between services and clients in a system. In this paper, we present our cloud-based Service Security Lab that supports the on-demand creation and orchestration of composed applications and services. Our cloud platform enables the testing, monitoring and analysis of Web Services regarding different security configurations, concepts and infrastructure components. Since security policies are hard to understand and even harder to codify, we foster a model-driven approach to simplify the creation of security configurations. Our model-driven approach enables the definition of security requirements at the modelling layer and facilitates a transformation based on security configuration patterns.

A tutoring system for IT security

Due to the many vulnerabilities of todays computer systems, IT security education has become an important topic. For that reason, a new tutoring system is developed at the Institute for Telematics, Trier, that allows users to gain knowledge about security technologies and tools via a web browser interface. Unlike other systems, this tutoring system does not provide a restricted simulation environment. Instead, guided exercises are performed on a real system (Linux). In this paper, the user interface and architecture of the tutoring system as well as some implementation aspects and future enhancements are described.

openHPI - A case-study on the emergence of two learning communities

Recently a new format of online education has emerged that combines video lectures, interactive quizzes and social learning into an event that aspires to attract a massive number of participants. This format, referred to as Massive Open Online Course (MOOC), has garnered considerable public attention, and has been invested with great hopes (and fears) of transforming higher education by opening up the walls of closed institutions to a world-wide audience. In this paper, we present two MOOCs that were hosted at the same platform, and have implemented the same learning design. Due to their difference in language, topic domain and difficulty, the communities that they brought into existence were very different. We start by describing the MOOC format in more detail, and the distinguishing features of openHPI. We then discuss the literature on communities of practice and cultures of participation. After some statistical data about the first openHPI course, we present our qualitative observations about both courses, and conclude by giving an outlook on an ongoing comparative analysis of the two courses.

Introducing hands-on experience to a Massive Open Online Course on openHPI

Massive Open Online Courses (MOOCs) have become the trending topic in e-learning. Many institutions started to offer courses, either on commercial platforms like Coursera and Udacity or using own platform software. While many courses share the concept of lecture videos combined with automatically assessable assignments, and discussion forums, only few courses provide hands-on experience. The design of practical exercises poses a great challenge to a teaching team and gets even more challenging if these assignments should be gradable. In the course Internetworking with TCP/IP on the German MOOC platform openHPI, the teaching team conducted an experiment with three practical tasks that were implemented as assessed bonus exercises. The exercise design was limited by the constraint that the platform software could not be adapted for these exercises and that there could be no central training environment to perform these assignments. This paper describes the experiment setup, the challenges and pitfalls and evaluates the result based on statistical data and a survey taken by the course participants.

Online assessment for hands-on cyber security training in a virtual lab

Online (self) assessment is an important functionality e-learning courseware, especially if the system is intended for use in distant learning courses. Precisely for hands-on exercises, the implementation of effective and cheating-proof assessment tests poses a great challenge. That is because of the static characteristics of exercise scenarios in the laboratories: adopting the environment for the provision of a “unique” hands-on experience for every student in a manual manner is connected with enormous maintenance efforts and thus not scalable to a large number of students. This work presents a software solution for the assessment of practical exercises in an online lab based on virtual machine technology. The basic idea is to formally parameterize the exercise scenarios and implement a toolkit for the dynamic reconfiguration of virtual machines in order to adopt the defined parameters for the training environment. The actual values of these parameters come to use again in the dynamic generation of multiple-choice or free-text answer tests for a web-based e-assessment environment.

Lightweight ad hoc assessment of practical programming skills at scale

There is a great demand for hands-on training in engineering education. In the context of a Massive Open Online Course (MOOC), assessing these experiments manually by teaching assistants is not possible owed to the high number of participants and the resulting workload for the teaching team. Systems for machine-based assessment of coding tasks are existing, but not necessarily available publicly, or not prepared to handle the massive amount of users in a MOOC. Definitely, they are not available “ad hoc”, but require a certain amount of effort to be integrated in the MOOC platform or to be made available for the students in another way. Time and money to provide the required effort is not always available. This work presents a lightweight solution for the assessment of practical programming exercises, based on third party online coding tools. The solution was introduced as a part of openHPIs Web-Technologies course. The basic idea is to prepare a task in an available online tool, along with a piece of code that is able to evaluate the participants solution. In case of success the participant is provided with a password, which in return serves as the answer for a fill-in-the-gap question in a standard quiz as provided by the openHPI MOOC platform, and thus allows for automatic online assessment based on practical coding exercises.

Tele-Board: Enabling Efficient Collaboration In Digital Design Spaces Across Time and Distance

Design Thinking is an approach for innovative problem solving. A typical characteristic of this approach involves multidisciplinary teams and the extensive use of tangible tools such as sticky notes, whiteboards and all kinds of prototyping materials. When team members try to collaborate from separate locations their traditional way of working becomes nearly impossible. A number of computer supported collaborative work systems exist, but there still lacks acceptable support for teams applying methods like Design Thinking. We have created an environment that allows these teams to work together efficiently across distances, without having to change their working modes. The Tele-Board prototype combines video conferencing with a synchronized whiteboard transparent overlay. This unique setup enables regionally separated team members to simultaneously manipulate artifacts while seeing each other s gestures and facial expressions. Our system s flexible architecture maximizes hardware independence by supporting a diverse selection of input devices. User feedback has confirmed that the Tele-Board system is a good basis to further enable collaborative creativity across distances while retaining the essential feeling of working together.

Enhancing a virtual security lab with a private cloud framework

Tele-teaching and hands-on exercises are of major importance in modern cybersecurity training. The Tele-Lab platform provides a virtual training environment using virtualized computers and networks, accessible via the Internet. With the rise of Massive Open Online Courses, it is also desirable to have such lab environments available. To make Tele-Labs virtual laboratory environment more flexible, scalable and faster, a private cloud framework should become the new basic layer to control and manage virtual machines. This paper explains the integration of OpenNebula into the existing software and implementation of an additional middleware layer that takes advantage of the cloud frameworks functionality.

Security in Tele-Lab — Protecting an online virtual lab for security training

The rapid burst of Internet usage and the corresponding growth of security risks and online attacks for the everyday user or the enterprise employee have emerged the terms Awareness Creation and Information Security Culture. Nevertheless, security education widely has remained an academic issue. Teaching system or network security on the basis of practical experience inherits a great challenge for the teaching environment, which is traditionally solved using a computer laboratory at a university campus. The Tele-Lab project offers a system for hands-on IT security training within a remote virtual lab environment — over the web, accessible by everyone. Such a system is inherently exposed to various security threats, since it has to provide full access to virtual machines running attack tools for potentially malicious users. The paper at hand introduces usage, management and operation of Tele-Lab as well as its architecture. Furthermore, this work focuses on possible attacks, the challenges when securing such a system, and shows how to set up an infrastructure that ensures the main security objectives identified as authentication, authorisation and availability.