Scientific publications

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.

Cyber-physical systems interact with their physical environment. In this interaction, non-functional aspects, most notably timing, are essential to correct operation. In modern systems, dynamism is introduced in many different ways. The additional complexity threatens timely development and reliable operation.

The use of mobile devices is often limited by the lifetime of their batteries. For devices that have multiple batteries or that have the option to connect an extra battery, battery scheduling, thereby exploiting the recovery properties of the batteries, can help to extend the system lifetime. Due to the complexity, work on battery scheduling in literature is limited to either small batteries or to very simple loads.

The Analytical Software Design (ASD) method of the company Verum has been designed to reduce the number of errors in embedded software. However, it does not take performance issues into account, which can also have a major impact on the duration of software development. This paper presents a discrete-event simulator for the performance evaluation of ASD-structured software as well as a compositional numerical analysis method using fixed-point iteration and phase-type distribution fitting.

Synchronous dataflow graphs (SDFGs) are used extensively to model streaming applications. An SDFG can be extended with scheduling decisions, allowing SDFG analysis to obtain properties like throughput or buffer sizes for the scheduled graphs. Analysis times depend strongly on the size of the SDFG. SDFGs can be statically scheduled using static-order schedules.

In this paper we address the problem of sink placement for Gossip-based Wireless Sensor Networks (GWSN). Sink placement plays an important role in planning and deployment of sensor networks. It is an efficient means to improve performance and achieve design objectives. Sink deployment requires an optimization strategy to search a space of possible placement options, and a performance evaluation method to assess the quality of different sink placements.

This chapter reflects on Falcon, a project to advance automation inwarehouses. Its main results and their impact as well as the project’s process arediscussed. The impact of Falcon on its industrial partners mainly concern model-based methods, of which strengthening the inception of the new architecture forsystem-level control of warehouses is a good example.

The warehouses of the future will come in a variety of forms, but with a few common ingredients. Firstly, human operational handling of items in warehouses is increasingly being replaced by automated item handling. Extended warehouse automation counteracts the scarcity of human operators and supports the quality of picking processes.