Safe, Ethical and Secure (Embedded) Computing

A couple years ago, I was tasked by my department to put together an innovative programme to train PhD students. After doing a consultation with all colleagues in our research away day in 2019, I could see a scenario that went completely against the picture of a stereotypical PhD student as a lonely character working on a hermetic topic which they carefully hide from the world until they can publish it causing fanfare and/or Earth-shattering consequences. Instead, what emerged was the desire for a strong sense of community, and emphasis on resilience and mutual support. Among the research topics we should emphasise, the list that emerged included green computing, explainable and safe AI, trustworthy decision-making in humans and machines, and ethical digital technologies. This was a very valuable exercise, and helped us in understanding the long term aspirations of the department in terms of research.

But then the covid 19 pandemic happened, and all research activities in the department were deprioritised so we had enough manpower to cope with the heavy workload caused by the move into online teaching. The plans for the innovative doctoral traning were suspended, and only resumed in early 2021. By then, with Paul Cairns as the new head of department and Ibrahim Habli as deputy head for research, the long term research vision for the department had been aptly summarised as safe, ethical and secure computing. And the new doctoral training centre was chosen to be a key instrument in realising that view, providing fully-funded studentships to students willing to work on high-impact research in those areas. So I took on the challenge and, with excellent support from the department's admissions team, managed to advertise, interview and recruit the first batch of PhD students for SEtS, the department's Doctoral Centre for Safe, Ethical and Secure Computing. They started their journey towards a PhD two months ago, and their topics cover areas as diverse as machine learning for cocoa plant disease identification, wireless networking for swarm robotics, monetisation strategies and player well-being in online gaming, and formal proofs for security-related properties in robotic systems. Interestingly, two of them are former EMBS students, and one of them appears in the EMBS Design Contest hall of fame! I am now meeting them on a weekly basis, trying out a number of new training initiatives, and gathering feedback on how to improve the training process for future cohorts.

So while the focus of the doctoral centre is much wider, there are many opportunities for research work in the area of embedded systems. The application process will be open over the next two months, so feel free to contact me if you are interested in pursuing a PhD in our doctoral centre. I'll be happy to discuss a potential research topic, or to introduce you to colleagues that do work in the areas you might be interested in. Find more details about my research areas, and my contact information, here.

Who would not want to be part of a centre with the acronym SEtS and with a Venn diagram showing the intersection of its three main areas as its logo?

EMBS Design Contest 2020

 

One year has passed since I wrote the last entry to this blog, and everything is so different now. We had to adapt to a very complex situation, and all our teaching had to be done online this academic year. It was particularly challenging for embedded systems, which in York has always been taught as lab-centric topic. With no access to the labs, we had to work hard to achieve the same learning outcomes using design tools and simulators that could be run by students in their own computers. We had a couple issues, particularly with creating and deploying virtual machines with pre-installed tools, but given the circumstances everything went well.

Another challenge was this year’s EMBS Design Contest. The traditional format where students run against the clock to create an ad-hoc wireless network across the Computer Science building was clearly not possible this year. After thinking about it for several weeks, I was ready to cancel the contest when I had an idea that would be suitable for our circumstances. Since I had added some new material to the part of EMBS that covers platform-based design and task mapping algorithms/heuristics (as I was forced to reduce the content on embedded wireless networking due to no access to the labs), I thought I could explore that type of problem and formulate a challenge that people could address in a distributed way.

The problem I devised was to map a large application model (44 tasks, 68 inter-task communication flows) to a multi-core platform based on a 2D-mesh network-on-chip. The application tasks and communications were characterised, respectively, by their processor utilisation and network link utilisation at nominal frequencies for the cores and interconnect. The objective was to find a mapping, over the smallest 2D-mesh platform and running at the smallest fraction of the nominal frequencies, but without over-utilising any processing core or network-on-chip link. This is an NP-hard problem that I’ve addressed in my research (together with several of my post-doc researchers, Master and PhD students), but using response time analysis instead of utilisation-based tests. In either case, there are no known optimal algorithms for this problem, only heuristics that do not guarantee optimality.

Before releasing the problem, I had to make sure it was challenging enough, and that it had at least one valid solution. To do that, I have created a valid mapping for a fairly thin application model onto a 4x3 network-on-chip platform. I then inflated the utilisations of tasks and communications of that thin model until that mapping was nearly breaking the utilisation bound of the platform at arbitrary but realistic frequency levels. The inflated application model was then be the problem I posed to the students (divided in four groups), and I had a good solution that I knew was valid (my chosen mapping for a 4x3 platform) and certainly achievable by the students with a bit of effort.

Once the challenge was released, I monitored the progress of all four groups (and had one videoconference session with each group) over the 2.5 days of the contest. Students were not allowed to choose their groups, and each group had 8-10 members. I’ve noticed that only 2-5 members of each group were actively working towards a solution to the design challenge. In past years, when the design contest happened in the lab, it was common to see 2-3 students taking the lead, but then all other students would engage or at least learn from the solutions attempted by the group. In the case of remote/online groups in 2020, that “side-learning” situation (i.e. students learning from students) did not really work. This could be an undesired consequence of online groupwork, but could also be related to the covid circumstances, or to the heavy workload at the end of the teaching term (especially when running the contest over 2.5 days instead of an intensive lab-based 2h competition).

Nonetheless, the achievements of the groups were laudable. Three of the four groups provided valid solutions to the problem. Group 4 actually found my original solution on a 4x3 platform, using a clever constructive heuristic that clustered together tasks that had high-utilisation communication flows between then, followed by some manual adjustments to tidy up the mapping. But the winner of the EMBS 2020 design contest was Group 3, who came up with a valid mapping for a 5x2 platform, therefore using fewer processors than the solution found by Group 4 (and myself). Their approach was based on the use of Genetic Algorithms for task mapping, which was covered in the new lectures and practical exercises I added to EMBS this year. Remarkable work, based on an unusual network-on-chip topology, but fulfilling completely the rubric of the design contest.

As always, we close the blog post with a picture of the winning group, Group 3. Fittingly for 2020, the picture is a snapshot of a videoconference. The group members will receive their prize (a snack giftbox each) via post this year.

 

And for finding my original solution to the challenge, I decided to award an honourable mention to Group 4 and add their photo as well.

 

Finally, links to the complete EMBS Design Contest Hall of Fame, with pictures of the top teams from 2019, 2018, 2017, 2016, 2015, 2014, 2012, 2011 and 2010 (in 2013, no group managed to finish the challenge on time).

EMBS Design Contest 2019

Every year, students in the Embedded Systems module take part in a design contest. In 2019, three teams competed in the task of setting up a multi-hop wireless network that is able to transmit information across the Computer Science building. This time, two teams managed to complete the task within the 2-hour slot allocated for the contest. The winner team, who finished only a few minutes earlier, received a box of chocolates and was granted the honour of having a picture published in this blog:

The second group to finish also received an honourable mention, and a smaller picture in the blog:

Here is the complete hall of fame, with links to the pictures of the top teams from 2018, 2017, 2016, 2015, 2014, 2012, 2011 and 2010 (in 2013, no group managed to finish the task).

EU-funded SAFIRE Project Concluded

We have now finished the work in the EU-funded SAFIRE project. The goal of the project was to investigate and develop technologies and infrastructure that enable Reconfiguration-as-a-Service for dynamic smart factory systems and manufactured smart products. York's role in the project was to design an optimisation engine based on Evolutionary Algorithms that can tackle large reconfiguration spaces by using a scalable cloud-based deployment.

York's optimisation engine was integrated to the situation determination and predictive analytics modules created by project partners ATB and IKERLAN, respectively, using a secure infrastructure provided by The Open Group. That way, every time a new situation in the factory is detected (for instance, if a mixer breaks or if the cost of wires has increased significantly), the optimisation engine is informed about it and it can evolve a new configuration that takes the new situation into account.

That approach was applied to three different case studies proposed by the industrial partners of the project: ONA (metal cutting machines), OAS (paint-making factory) and Electrolux (smart industrial kitchen). The results were disseminated by many publications, talks and keynotes, as well as newsletters and press releases.

I mention the SAFIRE project in this blog to show that embedded computing is dealing with much larger systems these days - embedded into a factory! - in a trend which is often referred as Cyber-Physical Systems.

More information and details in the SAFIRE website, which also includes links to all public reports and deliverables, as well as open source distributions of the code developed within the project.

SAFIRE was funded by the European Commission within its Horizon 2020 framework programme under reference 723634.

EMBS Design Contest 2018

Once more, it is time to report on the annual EMBS Design Contest. This year, four teams worked against the clock to implement, test and deploy a simple multihop wireless communication protocol delivering packets across the Computer Science building, from the hardward labs all the way to my office.

And just like last year, we had a winning team completing the task in less than two hours and a honourable mention finishing only a few minutes later. So, following our tradition, the winning team got a box of chocolates and their picture here in the blog:

And as we did last year, we allow a smaller photo of the honourable mention team:

And to close the report, links to the pictures of the top teams from 2017, 2016, 2015, 2014, 2012, 2011 and 2010 (in 2013, no group managed to finish the task).

Best Paper Award at DATE 2018

Last year, I wrote in this blog about my major disappointments with the academic peer review system, motivated by a series of reviews that I judged unfair and biased and that prevented an interesting piece of research (jointly authored by myself, Alan Burns and Borislav Nikolic) from being published. Now I am happy to report that the work has been accepted and presented at the top European conference in design automation of electronic and embedded systems (DATE 2018), and it has received the best paper award in the conference's Embedded and Cyber-Physical Systems track. DATE 2018 received 766 paper submissions and had over 1000 registered attendees, which further boosts the importance of the paper acceptance and the award.

This doesn't make it easier to accept the peer review flaws we had to go through, but at least it enables the publication of the work and a better definition of the current state-of-the-art in the area of priority-preemptive wormhole networks.

A pre-print of the paper can be found in the White Rose repository.

EMBS Design Contest 2017

And it is time to announce the winners of the EMBS Design Contest 2017. The Contest took place a bit later this year because of some changes in the teaching plan, aiming to better cope with the reduction in the number of assessments (from three to only two now, one in Dec/Jan and another in Apr/May). The rules were still the same: class divided in teams, each of them trying to design, implement and deploy an ad-hoc wireless network that is able to send packets from the lab all the way to my office in the opposite end of the Computer Science building. All within two hours!

This time, the winning team managed to get their solution working within a few minutes of the deadline, and were rewarded with a box of chocolates and their photo in this blog:

EMBS Design Contest 2017 Winners

And for the first time ever, the race towards a working solution was really close, and a second group managed to have their solution working and delivering packets at the destination only a couple of minutes after the winning group had delivered their first packet, so I think it is fair enough to reward them with a Honourable Mention and a (smaller) photo in the blog as well (but no chocolates):

EMBS Design Contest 2017 Honourable Mention

Here, some links to the pictures of the top teams from 2016, 2015, 2014, 2012, 2011 and 2010 (in 2013, no group managed to finish the task).