Scientific publications

Model-based testing is one of the promising technologies to increase the efficiency and effectiveness of software testing. This paper outlines the evolution of model-based testing based on labelled transition systems, from purely theoretical developments in the eighties to industrially applicable tools now: from canonical testers to practical testers.

The tutorial at CONCUR will provide a practical overview of work undertaken over the last six years in the Multicore Programming Group at Imperial College London, and with collaborators internationally, related to understanding and reasoning about concurrency in software designed for acceleration on GPUs.

Online scheduling of operations is essential to optimize productivity of flexible manufacturing systems (FMSs) where manufacturing requests arrive on the fly. An FMS processes products according to a particular flow through processing stations. This work focusses on online scheduling of re-entrant FMSs with flows using processing stations where products pass twice and with limited buffering between processing stations.

Truck platooning for which multiple trucks follow at a short distance is considered a near-Term truck automation opportunity, with the potential to reduce fuel consumption. Short following distances and increasing automation make it hard for a driver to be the backup if the system fails. The EcoTwin consortium successfully demonstrated a two truck platooning system with trucks following at 20 meters distance at the public road, in which the driver is the backup.

Kahn and MacQueen have introduced a generic class of determinate asynchronous data-flow applications, called Kahn Process Networks (KPNs) with an elegant mathematical model and semantics in terms of Scott-continuous functions on data streams together with an implementation model of independent asynchronous sequential programs communicating through FIFO buffers with blocking read and non-blocking write operations.

Accurate link quality estimation is a fundamental building block in quality aware multi hop routing. In an inherently lossy, unreliable and dynamic medium such as wireless, the task of accurate estimation becomes very challenging. Over the years ETX has been widely used as a reliable link quality estimation metric.

Image-Based control systems extract information by a camera and an image processing algorithm. The challenge of such controllers is that the sensing latency deteriorates the control performance. Multi-core technology can be used to implement the sensing algorithm in a pipelined fashion. More processing resources potentially lead to better settling time.

The development of cyber-physical systems (CPSs) with mechanical, electrical and software components requires a multi-disciplinary approach. Moreover, the use of models is important to support trade-offs and design decisions early in the development process. Since the different engineering disciplines use different modelling languages and tools, this calls for a co-simulation framework for discrete and continuous models.

This article studies the scheduling of real-time streaming applications on multiprocessor systems-on-chips with predictable memory hierarchy. An iteration-based task-FIFO co-scheduling framework is proposed for this problem. We obtain FIFO size distributions using Pareto space searching, based on which the task-toprocessor mapping is obtained with the potential FIFO allocation being taken into account; then, the FIFOto-memory allocation is optimized to minimize the total memory access cost; finally, a self-timed throughput analysis method that considers memory and direct memory access controller contention is utilized to analyze the throughput.