The School of Electrical Engineering awarded Elli Leppänen, Henri Hentilä, Henrik Kahanpää and Alec Wright for their excellent doctoral theses at the Celebrating Excellence event. Read what Hentilä, Kahanpää and Wright think about their doctoral studies and what tips they would give to those dreaming of a doctorate.
Current job: post-doctoral researcher in Professor Visa Koivunen's research group
'In my doctoral thesis, I studied cryptographic key generation using the physical properties of wireless channels (e.g. WiFi or 5G networks). Encryption protocols require that each party possesses a shared cryptographic key, which, as the name implies, should be encrypted to actors outside the protocol. The sharing/generation of such a key is one of the main challenges of the protocol. The current solutions are not only computationally very demanding, but are also breakable by quantum computers. In my thesis, I investigate an alternative key generation method where the key is generated at the so-called physical layer of the network protocol, and this allows both low computation and quantum security. So physical layer key generation has been studied since the 90s, and my contribution is mainly on the theoretical side. For example, I have studied how efficiently a key can be generated in a given channel when both communication and working memory are somewhat limited.
The best thing about doctoral studies is the freedom. You get to decide what to study and how (how freely you do this depends on your supervisor, of course), and no one is breathing down your neck when results don't come out right away. Of course, such freedom also brings challenges: you are, in a sense, alone with your problem, and your research will only proceed through your own hands. I must also mention all the conference trips that allowed me to visit for the first time countries such as Scotland, Japan, and the US.
I also spent a year on a research visit to Princeton University (New Jersey, USA). It was a really interesting year, which went by faster than I expected. I also learned to appreciate a lot of things that work much better here than in Finland, such as street lighting. I would recommend such a visit to all doctoral students, if at all possible.
My advice to anyone considering doing a doctorate is to think carefully about the research problems that interest you, but also about who would be the most suitable supervisor. If you feel that you will need a lot of support from your supervisor, a younger and less well-known professor would probably be a better option, as they usually have more time and enthusiasm to get into the technical details of your research problem with you. On the other hand, if you feel you can do well on your own, and would like better networking opportunities, an older and more renowned professor is probably a better option.
I recommend doctoral studies to anyone who is genuinely interested in a subject and wants to get to grips with it in depth. The subject does not have to interest you from every angle (for example, I was mainly interested in the mathematical side of my research problem), but it is important that you find something that you find really interesting.
It is also important that you are persistent enough and do not give up easily. Sometimes it can take months (or even years) before your work starts to produce the desired results.'
Current job: Quality Manager at the University of Tartu
'In my doctoral thesis, I studied the atmosphere of the Martian atmosphere. Although the density of the atmosphere on the surface of Mars is only about 2% of the surface density of the Earth's atmosphere, the wind is able to lift mineral dust into the atmosphere. Even when there are no storms, dust floats in the planet's atmosphere. The cause is thought to be small-scale whirlwinds called dust vortices. My thesis contributes to challenging this view.
When I started doing my doctorate in 2014, I had been working at the Finnish Meteorological Institute for 12 years. During that time, the Finnish Meteorological Institute, in collaboration with Vaisala Corporation, developed barometric pressure instruments for the 2008 and 2012 NASA Phoenix and Curiosity probes to Mars. I had been involved in the development of these instruments from the beginning, so my dissertation was a continuation of my earlier work. In addition to studying the dust spirals on Mars, my work addresses the uncertainties affecting the pressure measurements of the Phoenix and Curiosity probes and develops methods to overcome them.
Aalto University's School of Electrical Engineering is by far the most important institution in the field of space technology in Finland. I had also graduated as a master of science (technology) from there. But the choice was not a foregone conclusion. Aalto University was not in a position to fund my doctoral thesis, so I financed it with grants from foundations. Before applying to Aalto for a postgraduate degree, I looked into the possibility of doing a doctorate at the University of Helsinki, but they would not have been able to fund it either.
The best part was the feeling of being at the forefront of science. The scientific conferences were the highlights of my doctoral studies. The idea for one of the research articles in the dissertation was born during a coffee-table discussion at the EPSC conference of European Planetary Scientists.
I was a member of the NASA Curiosity science team even before I started doctoral studies. However, the postgraduate studies clearly allowed for a broader international networking than before. All the articles in the dissertation were carried out in international collaboration.
Research to advance science is a vocation: it's not worth doing for the money. Those considering postgraduate studies should also be aware that for many, debating is not the beginning of a research career, but the end. At least the School of Electrical Engineering does not usually hire its own newly graduated doctors. In most cases, continuing an academic career requires going abroad to become a post-doctoral researcher, and those positions are few and far between, not to mention professorships.'
Current job: Chancellor's Fellow in Audio Machine Learning, University of Edinburgh
'My doctoral studies focussed on digital emulation of popular music hardware, such as compressors and guitar amplifiers. Using a combination of deep learning and digital signal processing, we developed new methods that are now widely used in industry to create audio processing software for musicians.
I first learned of the Aalto Acoustics Lab, in the School of Electrical Engineering, during my MSc studies in Acoustics and Music Technology at the University of Edinburgh. It was clear that a lot of cutting edge and high-quality research in my field was coming from the Aalto Acoustics Lab. After meeting my supervisor-to-be, Professor Vesa Välimäki, at an audio engineering convention in Milan, I applied to join the doctoral programme.
I really enjoyed the working environment in the lab. As well as having great support and guidance from my supervisor, I was surrounded by many brilliant and passionate doctoral students. This meant I had an excellent professional and social life, and I really value the professional and personal relationships developed during my time at the Aalto Acoustics Lab.
I had the opportunity to attend many great conferences all across Europe during my studies (although less than I'd hoped, due to the unfortunate timing of the pandemic...). Additionally, I was lucky enough to spend 3 months working in Japan at the Yamaha Corporation. This was an amazing experience, where I got to apply the skills and knowledge I'd developed during the doctorate.
I would recommend doctoral studies in my field to anyone who is passionate about audio and audio technology. It's a great way to make a contribution to the field, with the potential to make an impact both in the industry and academia.
For those considering doctoral studies, I would say to get to know your future colleagues and try to find out what the working environment is like in your prospective institution. I think it's really important to be surrounded with knowledgeable people who can help you guide your research, and, equally important, to have supportive colleagues and a positive work environment.'
On Wednesday, March 13th, the School of Electrical Engineering gathered around to celebrate the most significant achievements and the best dissertations in 2023.
Doctoral education will prepare you for the most demanding expert positions in your field in the academia, companies and public administration. Start here if you’re interested in doctoral studies!
