*In this fourth episode of Teacher Talk, we get to meet Thomas Breugem: second year PhD student and currently also lecturer for the exercise classes of Analysis and teaching assistant for the same subject.*

**Can you tell us a little bit about yourself and your academic career?**

I studied Econometrics here at the Eramus University. After my master Operations Research I started my PhD under the supervision of Twan Dollevoet and Dennis Huisman. In my research I work together with the Dutch Railways (´Nederlandse Spoorwegen´, or abbreviated as NS).

I listen to a lot of different types of music. For example, one moment I am listening to Chopin and thereafter I switch to Vybz Kartel

**When did you start teaching?**

I have been a TA since the 2^{nd} year of my bachelor, so roughly 5 years ago. I thought a number of different courses in the first year, such as Matrix Algebra, and also some courses in the second year. I have really enjoyed being a TA during my studies. I started with the lectures when I started my PhD. Last year I gave the exercise lectures of the course Calculus 2, which is similar to the course Analysis we are teaching at the moment.

**What are your main areas of research?**

In my PhD I focus on crew planning at NS. This means, for example, that we optimize the rosters of NS personnel, while taking all kinds of difficult labour rules into account. In general my research focuses on railway optimization, which also includes problems like designing the timetable and determining the routing of trains through stations. What I really like about such problems is that you can actually see your research being applied in practice.

**What kind of music do you listen to?**

I listen to a lot of different types of music. For example, one moment I am listening to Chopin and thereafter I switch to Vybz Kartel. Let’s say I have surprised quite a few colleagues with my taste in music during our conferences abroad.

Most of the theory might seem difficult at first, but the majority of the concepts get relatively easy after you solved, say, 20 exercises.

**Do you enjoy the teaching aspect of your PhD and what is your favourite aspect of teaching?**

Yes, I think teaching is a nice addition to a PhD. What I like most is the interaction with students. It is interesting to see how each student approaches the problems in their own way. I also like the academic development students go through. For example, the difference between students in block 1 and block 5 is huge!

**How do you prefer to spend your free time?**

When I have the time I like to cook. During the weekend, for example, I often try to make some difficult dish. I am also a fan of a fancy dinner once in a while, something I try to do regularly with my friends. Furthermore, I enjoy going out for a jog and occasionally play squash with some friends of mine.

**What do you expect from students? And do you have any tips for this course?**

I expect students to be motivated and to try their best to understand the material. On top of that I think it is important that students are social and work together in the tutorials. I have to mention that most students in our program are a pleasure to work with.

My main advice would be to practice until you really feel confident with every part of the material. I try to stress this during the tutorials and exercise lectures: most of the theory might seem difficult at first, but the majority of the concepts get relatively easy after you solved, say, 20 exercises.

Although I was not able to understand all of it, the ingenuity of the whole thing really struck me. How could such `simple puzzles’ be so super difficult? That is when I decided to go into research.

**What is your favourite formula/theorem?**

That would be the P versus NP problem: imagine you want to visit all the capitals in Europe in a certain number of days. Of course, you need to determine whether that is possible before you start your trip. That doesn’t seem like an easy problem right? The funny thing is that, once you know the route, it is easy to check whether you will be back in time. That is, checking whether your solution is correct is simple compared to finding the actual solution. Although this might seem obvious, the mathematical equivalent of this statement (the P versus NP problem) has never been proven. In fact, you can win a million dollars if you solve it! I think it is a fascinating problem.

**If you were a pizza, what kind of pizza would you be?**

For a good pizza you need a good base so I would start with the classic tomato sauce and cheese. Furthermore, I would definitely add rocket to add a peppery taste and some serrano or parma ham on top, which should get nice and crunchy. Finally, I would finish it off with some pepper to give it some spice.

**When did you decide to go into research?**

I decided that I wanted to do research when I was in my first year of the bachelor. It was basically due to the P versus NP problem, which I first saw during the Linear Programming course. It was something that really fascinated me. I decided to buy a book on the topic, which was of course way to difficult back then. Although I was not able to understand all of it, the ingenuity of the whole thing really struck me. How could such `simple puzzles’ be so super difficult? That is when I decided to go into research.

My biggest hero? That would be Twan Dollevoet of course

**What are your plans for the future?**

In the short term I am going to work on my research for NS. We have a few interesting topics that we want to look at in the coming years.

I still have to decide what I want to do after my PhD. To be honest, I am not much of a planner. I think I will go into business eventually, as I think it would be an interesting experience, but I also like the freedom and intellectual challenges you find in academia. Maybe I will just try to do both of them.

**Who is your biggest hero in the academic field?**

That would be Twan Dollevoet of course. No, on a more serious note, I don’t really have a hero. If I can list multiple people who have inspired me, I would say the colleagues and teachers I have worked with so far. Most of them were and still are a great inspiration in my (ongoing) development as a researcher.