Publications

Blended education, the combination of traditional face-To-face education with online possibilities, is seen as the way for the future in education. Challenge for course providers is to learn how to offer blended education and to make the transition toward blended education. In this paper, we evaluate a first version of a blended course.

Internet of Things (IoT) is triggering changes in lighting industry from the traditional closed and propriety systems to flexible, interoperable and service oriented systems. To address the challenges of this transition and catering the specific requirements of lighting networks, an Open Architecture for Intelligent Solid State Lighting Systems has been proposed.

We present a three-step binding algorithm for applications in the form of directed acyclic graphs (DAGs) of tasks with deadlines, that need to be bound to a shared memory multiprocessor platform. The aim of the algorithm is to obtain a good binding that results in low makespans of the schedules of the DAGs.

Image-based control systems are becoming common in domains such as robotics, healthcare and industrial automation. Coping with a long sample period because of the latency of the image processing algorithm is an open challenge. Modern multi-core platforms allow to address this challenge by pipelining the sensing algorithm.

Cyber-Physical Systems (CPS) are tightly coupled with the environment, and therefore it is important that interactions with the surroundings like Human-Computer-Interactions are performed very responsive. Since CPS are often embedded without traditional input devices, like in medical or automotive contexts, gesture recognition approaches are emerging.

The design and analysis of smart system behavior needs to bridge between worlds – both with regard to engineering methods and to the technologies central to adaptivity and thus acore functionality of smart systems-of-systems. We illustrate this in our domain, smart buildings, where AI technologies like rule based or probabilistic reasoning set the strategies that define the building’s adaptive behavior, but control loops firmly set in control engineering implement it.

This paper proposes methods for verification of (m, k)-firmness properties of control applications running on a shared TDMA-scheduled processor. We particularly consider dropped samples arising from processor sharing. Based on the available processor budget for any sample that is ready for execution, the Finite-Point (FP) method is proposed for quantification of the maximum number of dropped samples.

We present an analysis method that provides tight temporal bounds for applications modeled by Synchronous Dataflow Graphs and mapped to shared resources. We consider the resource sharing effects on the temporal behaviour of the application by embedding worst case resource availability curves in the symbolic simulation of the application graph.

Service-oriented systems are designed for interconnecting with other systems. The provided services face timing constraints, the so-called latencies. We present a high-level performance evaluation technique that can be used by a system designer to obtain distributions of these latencies. This technique is capable of capturing nondeterministic, probabilistic and real-time aspects in one go.

Cross-technology interference on the license-free ISM bands has a major negative effect on the performance of Wireless Sensor Networks (WSNs). Channel hopping has been adopted in the Time-Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4e to eliminate blocking of wireless links caused by external interference on some frequency channels.