Publications

Using a well-known industrial case study from the verification literature, the bounded retransmission protocol, we show how active learning can be used to establish the correctness of protocol implementation I relative to a given reference implementation R. Using active learning, we learn a model M R of reference implementation R, which serves as input for a model-based testing tool that checks conformance of implementation I to M R .

Node mobility is a key feature of using Wireless Sensor Networks (WSNs) in many sensory applications, such as healthcare. The Medium Access Control (MAC) protocol should properly support the mobility in the network. In particular, mobility is complicated for contention-free protocols like Time Division Multiple Access (TDMA).

We report about experiences at Philips Healthcare with component-based development supported by formal techniques. The formal Analytical Software Design (ASD) approach of the company Verum has been incorporated into the industrial workflow. The commercial tool ASD:Suite supports both compositional verification and code generation for control components.

Analyzing worst-case application timing for systems with shared resources is difficult, especially when non-monotonic arbitration policies like First-Come-First-Served (FCFS) scheduling are used in combination with varying task execution times. Analysis methods that conservatively analyze these systems are often based on state-space exploration, which is not scalable due to its inherent susceptibility to combinatorial explosion.

Gossip-based Wireless Sensor Networks (GWSNs) are complex systems of inherently random nature. Planning and designing GWSNs requires a fast and adequately accurate mechanism to estimate system performance. As a first contribution, we propose a performance analysis technique that simulates the gossip-based propagation of each single piece of data in isolation.

The warehouse system sales process leads from a specific customer request to a specific customer quotation. This process of configuring a warehouse system with existing components involves a sequence of steps which contain increasingly more details. In this chapter, it is shown by two examples that easy-to-use essential system simulation models can be applied early in the sales process with a good cost/benefit ratio.

Borate ester compounds are emerging as promising materials for lubricating systems. The main drawback of borate esters however, is the susceptiblity to hydrolysis. In this work, two kinds of N-containing heterocyclic borate esters were synthesized. Their hydrolytic stability and tribological properties as lubricant additives in rapeseed oil were evaluated.

This book discusses various aspects, challenges, and solutions for developing systems-of-systems for situation awareness, using applications in the domain of maritime safety and security. Topics include advanced, multi-objective visualization methods for situation awareness, stochastic outlier selection, rule-based anomaly detection, an ontology-based event model for semantic reasoning, new methods for semi-automatic generation of adapters bridging communication gaps, security policies for systems-of-systems, trust assessment, and methods to deal with the dynamics of systems-of-systems in run-time monitoring, testing, and diagnosis.

Today’s embedded systems have to operate in a wide variety of dynamically changing environmental circumstances. Adaptivity, the ability of a system to autonomously adapt itself, is a means to optimise a system’s behaviour to accommodate changes in its environment. It involves making in-product trade-offs between system qualities at system level.

In the medical domain there is a tension between the requested speed of innovation and the time needed to deliver a certifiable system. To ensure the required safety, usually a long test and integration phase is needed. To shorten this phase and to avoid late bug fixing, the aim is to detect faults (if any) much earlier in the development process.