# Work prospects

On this page, there are stories about alumni. About what they do in their daily life, and about how they got where they are.

### Mathematics is a hobby and a way to solve (social) problems.*Tuesday 22 March 2022 11:50*

*Mathematics was for Yanna a way of relaxation. So it is not a surprise that she chose a study with a lot of mathematics. She ended up, after a great search, with the Bachelor (and Master) in Applied Mathematics and has applied her mathematical knowledge to several projects. Some of those projects are explained below.*

**Skating motion modelling**

One of the fun module assignments I did was about motion modelling. Together with my peers, we decided to model the movements of a skater. To do this, I set up differential equations for someone who was making skating movements. This was quite difficult and I watched many videos of how skaters move. In this assignment, we used differential equations, programmed an animated movie, looked at what gravitational forces were involved and at what speeds they were moving, for example, at the drop-off at the start.

**The Solar System**

Modelling is an important part of mathematics. This came up again during the assignment to model the solar system. We modelled several planets orbiting around our sun and a moon around one of those planets and looked at how the system behaved. In doing so, it is important to pick the right speed for each planet/moon. Otherwise, they might fly out of orbit or burn because they get too close to the sun. We orbited a moon around our sun and looked at how the planets behaved in relation to each other. In addition to modelling and physics, programming was also involved during this assignment, which I enjoyed.

**Studying after the bachelor's degree in Applied Mathematics**

After my bachelor’s graduation, I decided not to say goodbye to mathematics just yet. I get very happy with mathematics, so it was logical to make the step to the Applied Mathematics Master. I decided to continue studying within Prof. Marc Uetz's research group, Discrete Mathematics and Mathematical Programming.

**Internship at UT-Start-up QbayLogic**

QBayLogic is a digital design and consultancy company. Their focus is on leveraging FPGA technology in domains with difficult mathematical problems and solutions that need low latency and high performance. FPGA (field-programmable gate array) is an integrated circuit consisting of programmable logic components. They can be programmed as logic functions such as AND and XOR. These functions can be, for example, decoders or simple mathematical functions.

My assignment was to write a program that checks if a function terminates, i.e. generates an answer for any input variable, or may get stuck in a loop. It was an exciting assignment because I was working out of my comfort zone: in a field linking mathematics with theoretical computer science. I learned a new programming language (Haskell) that I had not learned at UT and I learned what a formal language is (basically my own simple programming language) and how to program one.

The program that I created was to be used within the compiler that the company worked with. Such a compiler translates source code to computer code and simplifies the code when possible. The compiler cannot handle code that gets stuck in infinite loops, since this ultimately would result in an infinitely large FPGA chip, so this is where my program would come in handy.

**Graduating project in Berlin**

Through Marc Uetz, I received an interesting and challenging graduation assignment at the Technical University of Berlin. In Corona time, this meant that I mostly did my research alone in a room with occasional help from my German supervisor Prof. dr. Max Klimm and remotely, via online video calls, with Marc. My assignment was about the Price of Anarchy, which took me into the world of game theory.

The Price of Anarchy gives information about the possible outcomes of a game with multiple players. In particular, it compares the outcome when the players play selfishly with the optimal outcome reached by working together. An example of a game is the Prisoners Dilemma, in which the overall outcome is best if the prisoners work together, even though this does not make sense from a selfish perspective. You may not always achieve the greatest benefit yourself, but you do ensure that the group achieves the best result.

My assignment was about the Price of Anarchy of a specific, abstract type of game. This game can be interpreted as a situation in which there are several computers and many employees who at the same time all need multiple computers to run computations. The more employees use the same computer, the slower it becomes. Selfishly, everyone wants to use the fastest computers. However, by working together and optimizing the distribution of computers, the employees may be done earlier on average. I have proved that in such games, the average computation time if players play selfishly may be up to twice as long as if they work together. It is thus really valuable to hire a supervisor who can optimize the distribution of the computers.

**An experience abroad**

It is great fun to do a part of your study abroad. I did my research on my own in the office (due to Covid), but during lunchtime, we went for a nice lunch together, with all the department employees. Berlin is a hip and modern city with lots of opportunities to soak up culture and party in Techno Clubs or by going to a Rave. And my German has improved as well.

**Student Life**

As a student, your life doesn't just consist of math and studying. I was a member of WSG Abacus, attended many activities and joined committees, so I got to know many students. It gave me a good feeling to be a member of this cool study association.

I was also a member of the Green Team Twente for a year. We investigated how we could drive a race track with our hydrogen car in the most economical way. As a strategy engineer, I calculated how you should drive at certain points (e.g. a corner) to be as economical as possible. I was also the driver and we had a test day on the Zandvoort circuit. It is very special to drive on such a circuit with a hydrogen car that drives 15km per hour, while Max Verstappen drove laps of over 300km/h. In the 2018/19 academic year we not only became European Champions, but in June 2019 we also became World Champions in London. It was great to be part of such an enthusiastic team.

**What’s next**

I recently completed my master's degree in Applied Mathematics cum laude. And now, I am looking for a (research) job where my expertise in network/graph theory, game theory, optimization, automata and programming come in handy. Looking forward to my next challenge.

### Mathematical calculations save lives*Tuesday 1 June 2021 14:41*

After obtaining her Bachelor's degree in Applied Mathematics, Giske Lagerweij decided to take up the Master's programme in Applied Mathematics to become an expert in solving societal challenges from technology to healthcare. Since two years, she is a scientific researcher at the National Institute for Public Health and the Environment (RIVM) and is involved in conducting research and making calculations of the burden of infectious diseases.

**What ultimately made you decide to pursue a Master's degree in Applied Mathematics at UT?**

"I chose to do a Master's programme in Applied Mathematics mainly because the lecturers and professors saw merit in my desire to do something medical. I didn't want to make timetables for a hospital, I wanted to go into a hospital and do something cool with my maths. I was allowed to take electives at BMT and TG, and I wrote to hospitals, the Roessingh and companies for an internship assignment."

**As you mentioned, you wrote to various medical institutions for an internship assignment. You eventually ended up at the Medisch Spectrum Twente in Enschede. ****What did your internship assignment entail? **

"I did my internship at the Department of Nuclear Medicine, and it was mainly about PET scans (positron emission tomography). A patient is injected with a radioactive substance, this substance decays and the degree of decay is measured. The degree of decay is converted into images, and with these images, doctors can determine the location and size of (abnormal) tissue. In this way, patients can be treated better, because the location of the tumour, for example, is properly determined and the surrounding tissue is not irradiated. I focused on tumour tissue. However, the conversion of decay into images is not always very reliable; there is a lot of noise on the line. My assignment was to find out whether you can determine which pixel in an image is "noise" and which pixel is (possibly) a tumour.

I think the broad knowledge you gain from studying applied mathematics helped me enormously. The assignment was applied, but because of the broad insight you gain during the study, you start looking in a direction for the solution (and sometimes this direction is wrong and you have to change your plans after three months). As a mathematician you have a wide range of knowledge, usually not in detail, but approximately, after which you can of course go into depth at a later stage by specialising."

**Was this also the moment when you knew you wanted to continue in healthcare after graduation? **

"Yes indeed! I have been interested in technical and medical matters since secondary school. Before I went to study at UT, I was in doubt between mathematics and medicine (technical). Medicine was soon dropped, then I had to choose between Applied Mathematics or Technical Medicine. There is mathematics everywhere, so I knew that somewhere along the way I would be able to fulfil my wish to study a programme that offered the combination of mathematics and something medical. In the end, I decided for the bachelor's and later the master's programme in Applied Mathematics."

**After you graduated, you were not done learning and chose to do a PhD in the research field of epidemology in Utrecht. ****How did you get the idea to do PhD research?**

"I ended up in Utrecht via a small diversions - I used to work for a software company in Deventer. Although I always said that I absolutely did not want to do a PhD, I changed my mind after two years of working in the business world. I found out that a PhD position would not be such a bad plan. I wanted more depth and I missed the link with mathematical applications in the medical field. Nothing is as changeable as the human being, right?

The choice for Utrecht was a coincidence, they offered a nice PhD assignment where they were looking for someone with a maths / economics background. I was on the edge of epidemiology, the really technical maths side. During my PhD, I also completed the full master's programme in Epidemiology. This master's opens doors for researchers without a medical background to still be able to take on medical issues.

With my mathematical background, during my PhD I focused on the (economic) evaluation of preventive interventions for cardiovascular diseases. This meant analysing prediction models, writing (time-consuming) scripts, converting problems into applied solutions, thinking logically about ‘how should I approach this problem?’ And what knowledge can I use from my master's degree to tackle this problem?"

**You have now been working at the National Institute for Public Health and the Environment (RIVM) for almost two years. What is your work about as a scientific researcher? **

"My work involves calculating the burden of infectious diseases. This includes all kinds of infectious diseases such as HIV, influenza (flu), but also food-related infectious diseases such as salmonella, norovirus (stomach flu) and toxoplasmosis. In total, we calculate the burden of disease for some 41 infectious diseases. The burden of disease is a term used to express the number of human lives lost, through disability and/or premature death, for a particular (infectious) disease. In addition, I also work on mathematical models for other purposes, such as predicting infections or calculating the costs and benefits of interventions to prevent/reduce infectious diseases.

And in case you are wondering, am I also working on COVID19? Yes, I also work on COVID-19 related issues, both calculating the burden of COVID-19 and making mathematical models."

On the RIVM website, I learned that 'living as healthily as possible in a safe and healthy living environment' is the goal of the RIVM. That is, of course, a wonderful aim and we all benefit from it in this society. The RIVM's scientific research has three content areas: Infectious Diseases & Vaccinology, Public Health & Care and Environment & Safety. You are positioned within the domain of Infectious Diseases & Vaccinology. During your Master's degree in Applied Mathematics, you had heard about the RIVM and it seemed like an interesting employer.

**Why do you think the RIVM is the right employer for you and especially within the domain of infectious diseases & vaccinology?**

"I think all domains have a lot to do with mathematics, there is a lot of calculation within the domains. I happen to work under this domain, but there are at least as many mathematical models or mathematics is applied within the other domains. After all, mathematics is in everything, whether it is modelling the spread of (infectious) diseases, calculating costs and benefits or of course a lot of statistics when analysing patient research, on which many epidemiologists work.

Naturally, I use the knowledge from my mathematical past in the performance of my work. Coincidentally, I recently applied basic calculus, because I was looking for a term in such a way that my (probability distribution) function actually became a probability distribution function. All integral and differentiation rules were used again. There are no specific subjects that I apply or use extensively in my work at the moment, it is mainly the combination of subjects and the experience of bringing together the knowledge from various subjects. It is really the total package that I use, the analytical ability to see connections, ask good questions and think logically. Combining linear algebra, scientific computing, statistics and probability, calculus and programming into one."

**Can you give an example of a project you have worked on? **

"Every year, a number of reports are published on the occurrence of infectious diseases in the Netherlands. These reports present the burden of disease. I am involved in conducting research, which can sometimes serve as the basis for advice. My contribution is mainly in picking up tasks quickly, and because as a mathematician you develop an overview that enables you to quickly see what you have to do, what happens in some cases, how things fit together and in which direction you can find the solution."

**You are not currently working on projects within the RIVM together with the UT. Perhaps this will happen in the future. When you think back to UT, what do you immediately think of? **

"I think of the (special) lectures of certain teachers, the solidarity between students and sometimes also teachers, the friendly atmosphere of the UT, the nice study association Abacus, the doors of teachers that were open, etc."

**Would you recommend study seekers to pick up a master's degree in Applied Mathematics? **

"YES! I said before that mathematics can be used everywhere! You are an indispensable link in society, you can use and apply your knowledge everywhere. It is difficult to explain to third parties what an (applied) mathematician can do exactly. Besides enthusiasm, you need (a lot of) perseverance, but in the end it's true: nobody can do without mathematics and therefore not without mathematicians either! In your work environment it won't happen often that you collaborate with several mathematicians who have studied the same as you. You are often an exception within the group, but that also makes it very special. You can easily adapt and empathise with others making you a valuable colleague within the group."

### How the film Twister determined Nadia’s future*Tuesday 19 January 2021 18:11*

‘When I first saw the film Twister, I knew for sure: I want to research extreme weather like tornadoes, cyclones and thunderstorms in the future!' Nadia says. Currently Nadia is doing a PhD research titled Tropical cyclone flood risk under climate change and has made her dream come true. She constructed a mathematical model that can analyze tropical cyclone activity all around the globe. Nadia: 'We need to make a targeted risk analysis to be able to assess what the risks of a tropical cyclone are. We are also dealing with the fact that tropical cyclones strongly interact with environmental factors. To be able to simulate this, I applied statistical modeling, making full use of my mathematical background!’

**Why did you opt for the bachelor of Mathematics?**

Nadia: 'I knew early on that I wanted to dive in meteorology and extreme weather, but of course, you need a good basis for that. I quickly learned that our atmosphere and weather phenomena can be described using formulas and models, so you need to have a good understanding of how to work with those. After a visit to the open day at the University of Twente, it was very clear to me that this basis would come from the bachelor's programme in Applied Mathematics, especially in Twente. For me this was - and still is - a perfect choice.’

**Were you sufficiently challenged?**

Nadia: 'Of course I faced many challenges. That likely applies to anyone who decides to study. Life at a university is completely different from what you were used to. Just think about the study pace, that's a bit higher at a university of course! In addition, I went to live on my own and had to take care of myself. Not only your study life changes, but also everyday life.’ So what do you have to think about? She continues: ‘Just think of everything your parents used to do for you while you were still living at home: cooking your own meals, grocery shopping, laundry, housekeeping, etc. It may take a while before you find your drive, but then it will be really fun. I became a member of the study association Abacus, was on the introduction committee of mathematics to help new students get started by organizing a great introduction period and together with a number of fellow students I published an almanac. A really cool time!’

**Did the programme meet your stormy dreams?**

‘Yes, formulas, mathematical calculations and modelling are not to be missed! In the third year you can choose a minor in a different field than mathematics. I chose the minor Geo data & spatial modelling. This minor was not directly related to meteorology, but taught me how to make landscape maps for different target groups. At the same time, you learned how to assess the value of maps, what the symbols mean and how satellites work. We analyzed different sort of satellite products and what you can use them for, such as infrared maps, and black-and-white bands. All those bands are particularly useful in the field of meteorology, since they can show temperatures and water contents in the air and clouds. So there was already a bit of meteorology in my minor. I still benefit from choosing mathematics,' Nadia explains.

**Was the choice of a Master complicated?**

Nadia: 'Of course, for me, it was not at all. Unfortunately, the University of Twente did not offer a meteorological programme, so I had to go elsewhere. Because I gained such a fantastic foundation in my mathematical bachelor, I could easily go anywhere for my Masters. I chose the Master’s programme Meteorology Physical Oceanography & Climate (now called Climate Physics) in Utrecht. In this master I was very attracted to how the atmosphere works, and how extreme weather phenomena like thunderstorms and tropical cyclones are formed. During my master’s thesis, I did an assignment at KNMI. Using their own operational weather model, I looked at the influence of soil moisture on the temperature. The water in the ground can evaporate, hereby cooling down air temperatures on warm days. However, something went wrong in the model, causing air temperatures to easily exceed 40°C on warm summer days, which is not really realistic for the Netherlands. My bachelor’s degree in Applied Mathematics turned out to be really handy here! Using my mathematical knowledge, I built a new version of this evaporation model, which is now implemented in a new version of the operational weather model. Within my PhD research, I also regularly have to improve existing models by using my mathematical knowledge.’

**And now performing PhD research in the field of extreme weather?**

‘Yes, I still don't have enough of it all and am still learning a lot. Doing research on your favorite theme is, of course, a dream come true. It's incredibly exciting work,’ Nadia laughs. Nadia has built her own ‘synthetic model’ using her mathematical background. This model “creates” its own cyclones, taking into account different factors such as their general direction of movement and their interaction with the environment.

With this mathematical model you can make sure that there are enough cyclones along the coast to perform a risk assessment and calculate the probability that a tropical cyclone with a certain intensity will occur in any given year. Moreover, it is now also possible to say something about the change in these probabilities under climate change – regions that now have a 1% chance of being struck by a tropical cyclone of a given intensity in any given year, might see a doubling of this chance under climate change. This is because tropical cyclones are expected to grow stronger under climate change.’ Nadia says.

In America, tropical cyclone protection standards such as dikes and coastal walls are built for a 1-in-100-year storm (1% chance annually). These storms –locally known as hurricanes - cause enormous flooding and the local governments must be prepared for it. For comparison, in our country, protection standards are designed for a 1-in-10,000-year storm: the ultimate “super storm”. Nadia: ‘With my model we can calculate how high the waves will be and how high your dikes must be to protect the people. The heights of our dikes have been estimated using a similar approach, and are continuously re-calculated whenever new information on climate change and sea-level rise becomes available. Our dikes are therefore high enough and so solidly built that they can withstand the waves of strong storms. This is also utterly necessary: half our country is below sea-level and would be flooded in case such a dike would fail during a strong storm. The Netherlands would be bankrupt in no-time, since most of our economies is in the western part of the country, but also because our insurance companies will not be able to cover the costs in the event of such a large flood. It is therefore crucial to keep simulating any changes in sea-level under climate change, and to keep improving and maintaining our dikes wherever necessary.

The tropical cyclones that are raging over the Atlantic Ocean currently do not have the ability to reach Europe on full-force. But due to climate change, this might change. This is because the sea water is expected to get warmer under climate change, and tropical cyclones need sea-surface temperatures of at least 27.5°C to keep their intensity. Therefore, if warmer sea waters extend further northward, it becomes possible for tropical cyclones to reach Europe and even the Netherlands before they die out. A recent example of this was Hurricane Ophelia, which formed as a tropical cyclone in the Atlantic Ocean. However, after weakening a bit and becoming an extratropical cyclone (the strong type of storms we get here in Europe), it managed to keep enough of its intensity to struck Ireland as a hurricane-force storm in October 2017. Scientists expect such events to happen more frequently in the future.’

At this moment, Nadia's mathematical model can determine how the tropical cyclones are formed, how many will occur and how they move. In the future this model will be extended to also include the extratropical cyclones. This way, she can calculate how high our risk is for “the ultimate super storm”, and how we can improve our dikes to protect ourselves against it. Nadia: 'I am happy to do my part and protect the people with science!’

### Pranab Mandal, the international programme director of Applied Mathematics with plans.*Tuesday 19 January 2021 18:07*

How likely is it that a mathematician from India will become the Programme Director for Applied Mathematics at the University of Twente? Perhaps even greater than you think. Pranab Mandal was recently appointed as the Programme Director AM. He graduated in India in the field of Statistics & Probability, completed his PhD in the US and ended up in the Netherlands on his way back to India. Here he met his current partner - Nelly Litvak, also mathematician - and both are now working at our university.

**What makes the discipline of mathematics important?**

Pranab: "As a mathematician, you quickly learn to think analytically. Analytical thinking is in itself an abstract concept. By continuing to practise, you become an expert and you can go in all directions with it. However, to practice this, you need a concrete field of application. That area/discipline does not have to be mathematics. The advantage of applying analytical thinking to mathematics is that mathematics has many fixed rules, you can't deviate much. As a result, you quickly learn to stay within the boundaries. And that's what you learn with mathematical proofs".

"Analytical thinking is important in our Applied Mathematics department as well. Here, we place more emphasis on modelling a problem in society. To better understand the reality you make a model and analyse different scenarios. Based on this, you determine the best solution that comes closest to reality. Often the solutions you find are not applicable to just one problem but can be re-used to find solutions to other similar societal problems by making only minor adjustments to the model. So your systematic way of thinking is worth its weight in gold," says Pranab.

**How do you prepare students for societal challenges?**

"The world changes every day. The way a mathematician works also changes because the social problems that need to be solved are probably not the same every year. That is why it is nice that the methods (techniques) to arrive at the solution can be reused. The way of thinking remains the same, but the problems and therefore the challenges of the society change. Within the Applied Mathematics programme, we let students practise a great deal on this through the execution of different projects. It is, so to speak, a test phase for later when they go into society to tackle real problems. You learn a result, apply it and eureka, everything falls into place. Exercising project assignments is therefore very important. By continuing to practice this controlled way of learning, such as learning theory, understanding and applying it to assignments, you become better at it and you can apply what you have learned to various problems in society. That is why a mathematician is so valuable within science or an industry". Explains Pranab.

He continues: "To prepare students well for the future, they are given the most important components from each mathematical discipline and sometimes from other disciplines as well. By combining what they have learned, great results can be achieved. Of course, you go even deeper into the subject matter within the master's programme. After all, here you will be trained to be an expert within a certain mathematical field, with a broad knowledge of the subject. Even as a BSc graduate, you are able to think analytically, have a systematic approach to tackle social challenges and can build good models to imitate reality and are therefore broadly deployable".

**What mathematical research are you engaged in?**

"My expertise lies in the research area of filter theory: how to filter out noise from data so that you can see a subject better. You always make sure that there is a balance between your model that matches reality and the analysis you do. Because you don't always have all the data at your disposal to generate the perfect answer, you need to have a good balance between the data, your model and the analyses. But as an expert in my field, I cannot come to a solution on my own, I need other experts from other (mathematical) fields. There are always aspects you have to deal with that you can't find yourself, those data are provided by colleagues. You are a cog in a big picture. By dividing problems into pieces, different mathematicians who are experts in different fields, such as discrete mathematics, numerical mathematics, systems theory or even disciplines outside mathematics, can work on the same problem. Based on a colleague's results, the next mathematician can work further on the solution using his expertise on it. The point of view within mathematics is also often that you always work from your way of thinking within your research group. In other words, together – in a multidisciplinary way - you come to the best solution" according to Pranab.

**Can you give an example of what filter theory is all about?**

Pranab: "Within the research into the operation of radars, which is done in collaboration with Thales, for example, we can put a filter between what is detected and what one ultimately sees. Noise is removed, you could say.

Nowadays, many people have a security camera connected to their house. Such a camera is, of course, an expensive product, so you want to get the most out of it. Sensors detect movement, so it indicates if someone is walking in your garden. However, there is always a margin of error. By applying filter theory, you can enforce a more precise way of detecting and thus reduce the margin of error".

**Why did you choose to become the programme director in addition to teaching and doing research?**

"In addition to teaching and doing mathematical research, I have also been a study advisor for the AM master's programme. Thanks to this position, I have gained a better understanding of the university and its inner work. I have seen that participating in our university is seen as valuable. With the position of programme director, I want to create a better atmosphere both for the students (to learn) and for the lecturers (to teach excellently). For example, as Master's coordinator AM, I had to submit documents for the EER (education and examination regulations). Because of the EER, students naturally have a handhold and know their rights. Everything is carried out following these rules. On the other hand, this influences being creative in teaching or disseminating the knowledge of lecturers. Education within the Applied Mathematics department is going well, what could I improve? The workload of lecturers has increased enormously in recent years due to the way education is organized at the University of Twente and in general, in the Netherlands. I would welcome the fact that more lecturers can be hired to be able to (re)distribute the work, and therefore the workload, better. Of course, the work of a lecturer is not only about disseminating knowledge, but it also involves student guidance and sitting on committees such as the Committee on Quality of Education to guarantee the quality and the level of the education we offer. It must therefore also be possible to make time available for this. Also, the use of guest lectures by staff from companies, such as Thales, is good to consider. To some extent, this already happens, but could it perhaps be expanded? This is certainly a good way to stay connected to the industry. It also offers the students a glimpse into the kitchen of a scientist in the field" according to Pranab.

**What are the most important points of attention on which you want to focus as the programme director? **

Pranab: 'I would like to look at the balance between mathematics content and projects. I have the feeling that the use of theoretical results and the recognition that they are applicable to different situations are not sufficiently practised. Understanding the theorems and the required conditions, and using them to come to a conclusion is a great asset. Perhaps more projects will be needed to practise this. But that would mean that fewer mathematics subjects could be included. How to find a proper balance between these two? Of course, everything has to fit within the 3 years of the bachelor's programme. I would like to improve this balance.

I would also like to look at the workload of the lecturers, as I mentioned above. This is a point that I will really like to look at further. Of course, this will also benefit the students in the end".

**Do you have any tips for your (future) mathematics students?**

"Mathematics prepares you for everything, doors will open for you. Thinking analytically becomes your second nature and offers you many opportunities in society. To make the study successful you must enjoy mathematics and enjoy the journey. Occasionally, you also need to take your mind off from mathematics. That’s why it is important that you participate in different (extracurricular) activities within the programme or UT. It also prepares you as a better person in society. There is time for it, but you have to keep a close eye on your priorities. You shouldn't do this study (only) because it looks great on your Curriculum Vitae, you should do it - just like your other hobbies - because you enjoy it! And why shouldn't you enjoy it, the life of a mathematician is wonderful," Pranab laughs.

### Femke and Sjoerd at NS*Friday 15 January 2021 11:58*

#### Let's travel by train more often!

Sometimes it happens that alumni Applied Mathematics meet within a company. This also happened to Femke Woudstra and Sjoerd Gallmann. Both work at NS Stations, Femke is Director Station Management & Operations and Sjoerd is Manager Services Innovation & Support. Very different jobs, but both are aimed at providing the passenger with a good station experience and making the journey from door to door as easy as possible. They graduated in different periods (Femke in 1998 and Sjoerd in 2003), never got to know each other during their student life, but now appear to be colleagues within the same company.

#### The similarities

Despite the fact that Femke and Sjoerd were not fellow students, I was able to find some similarities. They are still very happy with their choice of programme from back then: Applied Mathematics. Both did a minor in which they followed several electives from the programme Business Administration. And when they graduated, they thought it was time to go out into the world and look for a great job. Student life was said goodbye and business was approached with great enthusiasm. Period as a student may have passed, but they still maintain the friendships they gained during their programmes.

#### What did you pick up from your programme?

Femke: "I can't say that I'm still using a lot of mathematics in my current job. However, the way of thinking that I learned from my mathematics programme still helps me every day in my work. Through the teaching methods I have learned to work in a structured way and to find solutions, to think logically and to be able to quickly draw conclusions from data. As an applied mathematician you are broadly deployable. In case of problems you often quickly see what is going on, what the cause and consequence of a problem is and how you can come to a solution. And you are not easily frightened by a complicated subject, because you know that if you immerse yourself in it, you can make a lot your own". Sjoerd agrees and adds: "In my role as manager of various innovative projects, I have to deal with colleagues from different disciplines, such as Computer Science and Business Information Technology. They deal with IT, so that it has disappeared from my job. All the innovations we work on have a strong IT component. By working closely with them, I still have to deal with them and I immediately understand where they want to go with their ideas and models".

#### What does the job of Station Management & Operations Director at NS entails?

Femke: "Very briefly, you could say that I am responsible for the daily operations at all stations in the Netherlands. Think about the fact that the stations are clean, intact and safe, that there is a good range of shops at the station and that there are good facilities at the station such as bicycle sheds, public transport bicycles, toilets, water taps and cosy waiting rooms. Everything to ensure that passengers can have a pleasant stay and feel safe at our stations". Of course Femke doesn't do this alone, her department consists of about 300 employees. In addition, her department cooperates with various external partners, who, for example, supply the cleaning staff and the staff in the bicycle sheds.

Femke: "We are of course a company with a profit motive, but at the same time we also have a social responsibility. We want passengers to feel safe, to be able to find the right facilities at the station and to be able to catch their train on time. That's why it's important that public transport is well connected and that passengers who come to the station by bike or car can park easily, so that they can continue their journey by train. Cooperating in organizing - in a structured way - how we can do things a little better for the passengers at the stations, how we introduce innovations, besides working with so many nice colleagues, makes my job very interesting".

#### What does a Manager Services Innovation & Support do?

Sjoerd: "As my job says, I am mainly concerned with the innovation of services at the station. I am responsible for initiating and implementing these innovations. We often wonder how we can make things easier for passengers. Of course I don't do this alone, I'm the manager of several project groups, so-called product teams, where we investigate how we can best serve the car driver and challenge him to continue his journey by train, how we can make the toilets at the stations more easily accessible, come up with innovations for luggage lockers and how we can get the cyclist to park their bike faster and finally how we can make the rental process of a public transport bike easier and more self-service. These are very interesting projects and we often come up with very nice and smart innovations, such as a new check-in and check-out zone with which you can easily check in and out your bicycle. Our ambition is very high, we want our stations to be world class and with our smart innovations we are sure we are succeeding in that".

#### NS Bicycle InnovationLab

Sjoerd works with several of his project groups under the umbrella of the NS Bicycle Innovation Lab. In the ever busier inner cities the bicycle is gaining more and more ground. In the Netherlands it is even the most important means of transport among rail passengers. "That is why the public transport bike is of great importance to NS passengers", says Sjoerd. "In order to support and accelerate growth we want to make cycling to and from the station easier. Together with many colleagues from many different backgrounds, we are working in a multidisciplinary team to improve door-to-door travel so that more passengers choose the train. By developing smart innovations, piloting them and implementing them in the country, we ensure that our passengers' journey becomes better and more pleasant. And by making more use of public transport and the bicycle, we also reduce traffic jams, which in turn is good for the environment. At a number of NS Stations we are testing various innovations together with passengers in daily practice in bicycle parking facilities. This project is called NS Bicycle InnovationLab. We are testing whether it works just as well in practice as we came up with on the drawing board. We are also testing how we can optimize payment times by developing a new check-in and check-out zone: you check in and out with your public transport chip card at a gate or at the check-in and check-out pillars. The costs of parking your bike is automatically debited from your account or you pay contactless with your debit card. We may even be able to place tags on bicycles that allow check-in and check-out to take place automatically. Enough challenges to test out and implement!

#### Conclusion

If you graduated in Applied Mathematics, have made a number of job switches, chances are that you are not directly involved in mathematics anymore. Indirectly, perhaps because you work together in a multidisciplinary team, such as Sjoerd. But if you end up in a position like Femke's, you will probably see algorithms, mathematical formulas or -models less frequently. But is that so bad? Apparently not, because you learn a lot more than mathematics alone. You can see through and pick up problems quickly and well, working together with a multidisciplinary team is easy, structuring and organizing is a piece of cake for you, and... you can be deployed in a lot of areas. Sjoerd and Femke: "Would we recommend the programme Applied Mathematics to future students? Yes, we would!"

### Nelly Litvak - International WomensDay*Friday 15 January 2021 11:52*

#### Do we still have to celebrate International Women's Day in these modern times?

On 8 March we celebrate International Women's Day. This year's theme is freedom. How free are we as women? For years, women have been fighting for self-determination, individual rights and freedom. Is it still necessary to create a special Women's Day? That's the question we asked Professor Nelly Litvak - from Russia.

#### How do you feel about International Women's Day?

Nelly: "In Russia this is very common and this day is celebrated like Mother's Day or Valentine's Day in the Netherlands. It is a national holiday for everyone, women get flowers or presents. This is very different in the Netherlands and Dutch women often wonder whether we should celebrate it still. I think it is an important subject to bring to the attention. There is no reason to think that women have less potential in doing scientific research or other work. Nevertheless, in percentage terms, few women work in science or in higher positions in business. Raising the awareness that we need to do something about this is good via days like this, but I think we should act as parents and give this to our children to break the current pattern of thinking. Women are disadvantaged by being women. Unfortunately, women are evaluated lower in education for the same quality of work (e.g. the study material used) and receive lower evaluations from students than men. This has been proven in several studies. The last time a woman won the UT education award was in 2006 and last year. Surely it took far too long that a woman won the award?! A public performance or presentation is poorly received if it is given by a woman. And why? If a man thinks he is the best in his profession, that is considered normal. If a woman says she's really good in her job, then suddenly she is a bitch or she is arrogant. If, on the other hand, we're modest, we're not considered professionals. So - unconsciously most of the time - we are judged more strictly on our behaviour. We actually have to get rid of this as soon as possible, and therefore organizing an international women's day or establishing the Hypatia chair, especially for women, is a good thing to keep doing. Until we are all truly equal and treated in the same way, and gender bias (gender inequality) is eradicated".

#### Who is Nelly Litvak?

Ever since she was a child, Nelly has known what she wants: to teach and pass on knowledge. In primary school she told her classmates `stories and long poems'. And at the age of 15 she knew for sure: she wanted to become a teacher at a university. And she succeeded, she is professor in Algorithms for Complex Networks at our university and is also part-time professor at the Eindhoven University of Technology and visiting professor at the Moscow Institute of Physics and Technology.

#### Who are your role models?

Nelly was born and raised in Russia and her great role models were her grandmother and mother. Her grandmother graduated in physics in the Stalin era. Due to circumstances her grandmother did not go to work in a state enterprise, but ended up in the classroom. "This turned out to be a perfect move. My grandmother has a passion for passing on knowledge and she has developed a program for special classes with deeper specialization in physics for the upper classes and has gained national fame (in Russia). Partly because of this, she later started working at a university. My mother was a journalist and during the perestroika many wanted to become a journalist and new TV channels were created every day. My mother then set up a training in journalism in order to meet the great demand for journalists. When the school became a national school, Queen Beatrix, accompanied by Prince Willem Alexander, visited her school. I am very proud of my mother, she founded a school, wrote many books, trained politicians in communicating and presenting or prepared them for a TV performance. Now she is 67 years old and she is a business coach with high esteem. I'm very proud of her and I like to live by her motto 'Always do something extra, there will come a time when those extra's will determine your life but keep adding those extra's'" Nelly says.

She continues: "As an adult, I have great respect for Madeleine Albright, an American politician and Democratic Party diplomat. She turned her life around when she was older and started a new career. She inspires me to always have a choice and to start or learn something new and that you can choose a different path at some point in your life. If you make that choice, always do it from the heart. So Madeleine actually acted just like my grandmother and mother. They, too, made a turnaround in their career/life and chose work that made their hearts beat faster and made a success of it. This is how I hope to live."

#### What big decisions or changes in your life did you make?

Nelly completed her studies in Russia and decided to take up a PhD. The perestroika period wasn't easy for Russian scientists. Wages were very low compared to the high salaries earned in businesses. But if you have a passion for science and pass it on, like Nelly, you have to make choices. By now Nelly was married, had a little daughter and decided to go for science anyway. "When the ruble went into complete crisis and scientists had no growth opportunities at all, a lot of Russian researchers went abroad. During this period I visited a congress in Prague - that was in 1998 - and there I met Professor Van Zwet from the Netherlands. He was impressed by my lecture at the congress and invited me to come to Eindhoven, Eurandum. At that time I had to make a difficult decision: Will I stay in Russia and stop with science or will I choose science and go abroad? Unfortunately my marriage was terminated and the offer to do 4 years of PhD research in the Netherlands made it a bit easier for me to make the step abroad. A few months later my daughter also came to the Netherlands. Quite a big step, but it certainly was a good decision" Nelly explains.

#### How did you end up at the UT?

"Although I had already carried out and completed a PhD research in Russia, I also took up a PhD research in the Netherlands and obtained my PhD at the TU/e in the field of Stochastic Operations Research. My co-promotor was Professor Henk Zijm. He also worked at the University of Twente and founded a new chair in Stochastic Operations Research, where I eventually became part of the team. Today, my main research interests are large networks such as online social networks, the World Wide Web, randomized algorithms and random graphs and recently also predictions for networks using machine learning. I love to teach, but I also like to make people appreciate mathematics more through popular scientific books, public lectures and social media," Nelly says.

#### What do you want to advice your female students?

Nelly: "Don't perpetuate the old-fashioned image of women in science, step outside the box and choose your own way and feel free to make that choice. Tell the world that women are just as good at research, education or any other job. There is no proof that women do less good work than men and don't let anyone say so neither. And at some point, we no longer need positive discrimination, scientific awards for women, international women's days, chairs for female researchers, etc.".

### Dirk Kroese*Friday 15 January 2021 11:50*

### Ever thought about an Australian experience during your programme? Dirk invites you!

Dirk Kroese received both his Masters (1986) and PhD (1990) from the Department of Applied Mathematics at the University of Twente. After his PhD he continued as Lecturer in the same department, where he taught Applied Probability and Statistics. During that period he met his Australian wife, had two children, and they decided in 1998 to go "Down Under". Dirk has been employed for the last 20 years by The University of Queensland (UQ) in Brisbane, since 2010 as a Full Professor in Mathematics and Statistics. He is well-known for his contributions to Applied Probability and Monte Carlo methods, and has over 120 publications, including 6 books. During our conversation, it became clear that Dirk finds it easier to communicate in English. Here are his reflections on his study and work at UT.

#### How do you remember Applied Mathematics?

Dirk: "I remember it with fondness. I chose UT (at that time it was called THT) because they offered a great depth and breadth of courses in Applied Mathematics and had just started an "Informatica" department with close connections to the AM department. Coming from a small village on the Veluwe, I though (then) that Amsterdam and Utrecht were a bit too exotic for me. Being able to live on campus was also a great advantage of UT. I learned a lot during my time here, and the lecturers placed great emphasis on rigour and proofs. I remember that we started with 6 analysis courses, just to get the basis right. When I further specialised in Applied Probability, it was great to have knowledge of many branches of mathematics, such as discrete mathematics, optimization, numerical analysis, functional analysis, measure theory, and complex analysis. Doing an Internship abroad, at the University of Texas (at Austin) opened me up to many new experiences. In addition, part of my PhD (1988-1989) was done at Princeton, under Erhan Cinlar, via an NWO scholarship. I found that the foundations I had been given in Twente prepared me well for my time there. Like Austin, Princeton was a wonderful experience, and I learnt many new thing."

#### AM persons of interest?

"The teachers I remember the most are of course my advisors Jos de Smit and Wilbert Kallenberg. They taught me how to do Probability and Statistics properly, and I'm forever thankful to them. Other teachers that I remember well are Frank Twilt and Wolfgang Wetterling. Frank was a fantastic teacher who taught complex function theory. Wolfgang Wetterling had the most wonderful lecture notes ("diktaat") on Functional Analysis. To this day I still use his notes if I want to look something up on functional analysis. I still think lecture notes are very useful for teaching and learning, and I have produced quite a few lecture notes myself. During my lectureship at UT we had a great Probability and Statistics group. Many, such as Wilbert and Jos, are retired now, but I still am in close contact with Werner Scheinhardt and was saddened to hear that Erik van Doorn had recently passed away. Both visited me in Australia. Werner invited me recently to give a lecture within the AM department. It's always nice to visit your alma mater, to reminisce with the people you know from the past, to meet the new staff members and to be able to share research findings" Dirk explains.

#### AM internship

Dirk: "During my AM programme, I did my (first) internship at Goudappel & Coffeng. The company was involved in traffic management modeling, and during that time I developed and studied a probabilistic model for the gap distribution between cars on a road. I also wrote software to make plots of my findings using their new plotter. I remember that certain staff members wrote these massive reports with lots of unnecessary details. I just stuck to writing a concise and precise report, as mathematicians do. As I mentioned earlier, I did another international internship at UT Austin. This was one optimal ambulance allocation, which was very interesting."

#### How multidisciplinary are you?

"I did not have much time for other disciplines during my programme. I have heard that this is different nowadays. That's good in some way, but can be detrimental if you don't lay a proper mathematical basis for collaboration first. After all, Mathematics is the language of Science and Engineering. We can only understand each other if we speak the same language. I now collaborate frequently with colleagues from other disciplines, in Engineering, Science, and Robotics. Our common ground is Monte Carlo simulation methods, Machine Learning, and Applied Probability. It is very interesting to work with engineers from different research groups on these projects," Dirk explains.

#### Collaboration with the UT

Dirk: "I would love to welcome students from the University of Twente and guide them through an internship or graduation project at the University of Queensland and share my knowledge with them. I have hosted many interns from Germany, France, India, and China, but surprisingly never a Dutch one. Within my own research I have regular contact with Werner Scheinhardt; a most pleasant collaboration that I would like to continue. It's always good to work on a project with colleagues outside your own university in order to be able to bring along a different insight and to achieve great results together."

#### Do you have tips for current AM students?

Dirk: "I do! Question everything (especially in this "post-truth" era), and always try to fully understand what you are learning. Find your own solutions and don't let yourself be tempted to look them up on the internet. If you persist in discovering your own solutions, you will establish better connections in your brain, and this will help you solve subsequent problems more easily. In addition, I would advise everyone to do part of their programme abroad. Not only does it enrich your academic knowledge, but it also makes you better appreciate what an interconnected, beautiful, and fragile place our World is. And, by all means, keep my department at the University of Queensland in Australia in mind for your foreign experience. ? "