The contribution The Reachability Problem for Petri Nets is Not Elementary by Wojciech Czerwinski, Slawomir Lasota, Ranko Lazic, Jerome Leroux and Filip Mazowiecki has won a Best Paper Award at the 51st Annual ACM Symposium on the Theory of Computing, to be held on June 23-26, 2019 in Phoenix, AZ.

This work, which was supported by a Leverhulme Research Fellowship, shows that the central verification problem for Petri nets is much harder than has been known since the landmark result of Richard Lipton in 1976. Petri nets, also known as vector addition systems, are a long established model of concurrency with extensive applications in modelling and analysis of hardware, software and database systems, as well as chemical, biological and business processes.

This year’s Warwick Postgraduate Colloquium in Computer Science, WPCCS 2018, took place on Friday 29th June. The colloquium, an annual student-run event, showcased research performed by the postgraduate research (PGR) students in Computer Science, the Centre for Discrete Mathematics and its Applications (DIMAP) and the CDT in Urban Science and Progress.

Continuing a new tradition for the colloquium, this year’s event was held in The Oculus, University of Warwick. In addition to presentations from students in each of the department’s research areas, staff and external speakers offered guest talks. These centred on language design patterns in 2018, the evolution and horizons of Field Programmable Gate Arrays (FPGAs), and WebEXR, an online high dynamic range image viewer.

Florin Ciucu, the director of postgraduate research studies in the Department of Computer Science, said of the event:

WPCCS is an excellent opportunity for our students to widely expose where they currently stand in their research. It’s a fantastic way for them to contribute by sharing their research experiences, ideas and visions with their peers and the wider research community.

WPCCS 2018 showcased over 45 presentations and 25 posters of the latest research in the Department of Computer Science. WPCCS aims to foster an air of collaborative research amongst the department’s PGR students and open many conversations between the department’s postgraduate researchers and others. Thank you to all who attended and participated, we look forward to seeing you again next year.

To find out more about WPCCS 2018 or to provide feedback, please visit https://warwick.ac.uk/wpccs18.

In the Logic, Semantics, Automata and Theory of Programming track of the 45th International Colloquium on Automata, Languages, and Programming (ICALP), three out of 30 accepted papers are by members of the department. ICALP is one of the most selective and longest established international conferences in computer science, and the flagship annual event of the European Association for Theoretical Computer Science. The papers are:

• Reducing CMSO Model Checking to Highly Connected Graphs by Ramanujan M. S., Daniel Lokshtanov, Saket Saurabh and Meirav Zehavi
• O-Minimal Invariants for Linear Loops by Shaull Almagor, Dmitry Chistikov, Joel Ouaknine and James Worrell
• When is Containment Decidable for Probabilistic Automata? by Laure Daviaud, Ranko Lazić, Marcin Jurdziński, Filip Mazowiecki, Guillermo Perez and James Worrell

On June 1st 2015, our Division of Theory and Foundations, jointly with DIMAP, organized DIMAP Logic Day 2015. The goal of the event was to bring together the UK community of researchers and graduate students interested in the study of logics, automata and games.

The event had an outstanding list of invited speakers from leading academic institutions and research labs (Nathalie Bertrand, INRIA Rennes; Antonin Kucera, Brno; Slawomir Lasota, Warsaw; Davide Sangiorgi, Bologna, INRIA Sophia Antipolis; Sylvain Schmitz, Cachan, INRIA Saclay, Warwick; James Worrell, Oxford) presenting recent advances in logic in computer science, and attracted over 40 participants from the UK and abroad.

Lei Shi, a doctoral student in the Department of Computer Science at Warwick, has received a top award for his work at UMAP, the premier international conference for researchers and practitioners working on systems that adapt to individual users.

UMAP 2014 was held in Aalborg, Denmark on the 7-11 July 2014. The conference spans a wide scope of topics related to user modeling, adaptation and personalization, and was sponsored by Microsoft Reasearch and the NSF.

Lei will begin a Warwick Institute of Advanced Study (IAS) Early Career Fellowship in October. More information on his work can be found at http://www.shilei.io

Research highlights the future of energy-aware high-performance computing

Leipzig, June 18, 2014. As reported in Inside HPC.

With energy costs a growing concern for High Performance Computing, Allinea Software will demonstrate its vision of a greener future with a preview of new tool extensions for application energy usage optimization at this year's International Supercomputing Conference (ISC'14) in Leipzig.

With larger numbers of data centers consuming over 1MW of power or having electricity bills topping $1M, energy is focussing the minds of the system sponsors and managers, says David Lecomber, CEO of Allinea Software.

Allinea Software worked with application performance experts at the University of Warwick to investigate novel energy and power measuring techniques for scientific application workloads.

Energy usage data is increasingly available at the system level, and our research also explored proxies for energy such as hardware counters to see where they could give deeper insight, said Professor Stephen Jarvis of University of Warwick’s HPC Performance Analysis Group.

The research supported the view that in many cases applications can reduce energy costs without adversely impacting actual run time.

Improving the green credentials of hardware and data centers is vital, and progress is good, but applications must also play their part. Energy optimization is a natural fit for our performance tools, adds Lecomber.

With the variety of workloads that HPC centers have, a ‘one size fits all’ strategy is a costly error – and so Allinea Performance Reports will provide information for application users and system managers to enable them to tune system and application parameters such as CPU frequency for optimal energy use for each application.

Our developer-centric tool, Allinea MAP, will allow scientific code developers to focus energy optimization down into the source code – making changes to the application to drive faster performance and lower energy consumption at the same time.

This research has been supported by the Technology Strategy Board's Emerging Technologies Energy Efficient Computing Programme.

On May 21 2014, our Division of Theory and Foundations, jointly with DIMAP, organized DIMAP Algorithms Day 2014. The goal of the event was to bring together the UK community of researchers and graduate students interested in the study of Algorithms, Data Structures, and Complexity.

The event had an outstanding list of invited speakers from the leading academic institutions and research labs (Alexandr Andoni (Microsoft Research Silicon Valley), Graham Cormode (Warwick), Edith Elkind (Oxford), Leszek Gąsieniec (Liverpool), Aleksander Mądry (EPFL)) presenting the recent advances in Algorithms and its applications, and attracted over 60 participants from over the UK and from abroad.