Scientific publications

Many technical products and systems nowadays have functionality that is largely determined by software, so called software-intensive systems. The requirements for software-intensive systems change over time, causing the system to evolve. We define evolvability as the ability of the system to respond to such changes.

Although agent technology fits naturally to the control of the massively parallel processes in warehouses, agent-based warehouse management and control systems (WMCSs) have hardly been used in industry. We argue that model-driven development of such systems is crucial for their industrial applicability.

To increase the confidence in the correctness of software components, we investigated the use of two complementary formal methods in industrial software development. We combine a commercial refinement checker, the ASD:Suite of the company Verum, with the academic verification tool Uppaal to encompass a larger range of verification possibilities.

Probabilistic model checking has been used recently to assess, among others, dependability measures for a variety of systems. However, the numerical methods employed, such as those supported by model checking tools such as PRISM and MRMC, suffer from the state-space explosion problem. The main alternative is statistical model checking, which uses standard Monte Carlo simulation, but this performs poorly when small probabilities need to be estimated.

Multirate digital signal processing (DSP) algorithms are often modeled with synchronous dataflow graphs (SDFGs). A lower iteration period implies a faster execution of a DSP algorithm. Retiming is a simple but efficient graph transformation technique for performance optimization, which can decrease the iteration period without affecting functionality.

The two-player mean-payoff game is a well-known game theoretic model that is widely used, for instance in economics and control theory. For controller synthesis, a controller is modeled as a player while the environment, or plant, is modeled as the opponent player (adversary). Synthesizing an optimal controller that satisfies a given criterion corresponds to finding a winning strategy for the controller player.

This paper presents a collaborative procedure for multiobjective global routing. Our procedure takes multiple global routing solutions, which are generated independently (e.g., by one router that runs in different modes concurrently or by different routers running in parallel), as input. It then performs multiobjective optimization based on Pareto algebra and quickly generates multiple global routing solutions with a tradeoff between the considered objectives.

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.