Scientific publications

We consider supervisor synthesis of Extended Finite Automata that are represented using Binary Decision Diagrams (BDDs). Peak used BDD nodes and BDD operation count are introduced as platform independent and deterministic metrics that quantitatively indicate the computational effort needed to synthesize a supervisor.

To architect and design a system, the stakeholder needs have to be satisfied by technical solutions, for which decisions on trade-offs have to be made. A trend is that the number of functions, components, and interfaces in systems increase, often by an order of magnitude or more, such that reasoning about the impact of a decision becomes increasingly hard and tracing its impact throughout the system is crucial.

Predictive maintenance strategies which estimate remaining useful life of system components ensure reliable availability of assets and low total costs of ownership by preventing breakdowns and down-times with timely and well-scheduled maintenance. The focus on the components’ life times falls short, however, to infer the system-level capability to achieve upcoming tasks, especially if these tasks vary either in the strain they cause for the system or in the environmental conditions in which the system needs to perform.

At the pre-concept stage, an architect explores the problem space together with various stakeholders, including engineers, marketing, and future users of the system. This requires competencies and tactics to communicate efficiently while maintaining a system-level scope. We present a practical Structured Problem Exploration approach to assist architects in exploring the problem space.

Cyber physical systems of systems operate on and with machine-generated data that form the foundation of many of their information-centric functions and processes. Especially within infrastructure systems of systems and the applications of the internet of things, data became an asset for additional tasks regarding their efficient and effective operations, e.

Keeping a vehicle secure implies provide of a long-term support, where over-the-air updates (OTA) play an essential role. Clear understanding of OTA threats is essential to counter them efficiently. Existing research on OTA threats often exclude human actors, such as drivers and maintenance personnel, as well as leave aside privacy threats.

This paper covers the Rigorous Examination of Reactive Systems (RERS) Challenge 2019. For the first time in the history of RERS, the challenge features industrial tracks where benchmark programs that participants need to analyze are synthesized from real-world models. These new tracks comprise LTL, CTL, and Reachability properties.

A well-known conformance relation for model-based testing is ioco. A conformance relation expresses when an implementation is correct with respect to a specification. Unlike many other conformance and refinement relations, ioco has different domains for implementations and for specifications. Consequently, ioco is neither reflexive nor transitive, implying that a specification does not implement itself, and that specifications cannot be compared for refinement.

Efficient code generation for image processing applications continues to pose a challenge in a domain where high performance is often necessary to meet real-time constraints. The inherently complex structure found in most image-processing pipelines, the plethora of transformations that can be applied to optimize the performance of an implementation, as well as the interaction of these optimizations with locality, redundant computation and parallelism, can be indentified as the key reasons behind this issue.

To handle the rigid power and energy constraints in the Digital BaseBand (DBB) of Wireless Sensor Networks (WSN)s, we introduce approximate computing as a new power reduction method. The Received Signal Strength Indicator (RSSI) computation is a key element in DBB processing. We evaluate the trade-off in RSSI computation between Quality-of-Service (QoS) and power consumption through circuit-level approximation.