Flower Power 2020 by Ideaal! (Abacus)

S Association magazine of W.S.G. Abacus

Rutger van der Graaf

The Pen Interview with...

Stichting RSA Vincent Bosboom

Current-Phase for Dayem bridges

Flower Power 2020

INDEX 4 4 5 23

Columns Chairman's Thoughts The Pen Your Story Dear Readers... Mathematical Current-Phase relationship 11 for long Dayem bridges

6, 14, 22 7, 17, 18 10 12 12, 13 16 21

Fun Interview Puzzles On the Couch Review Puzzle Solutions Memes Colour-In

Editorial Dear reader, About a month ago I heard I had to write my last editorial column for this year. I spend quite some time thinking about what it could be about and I actually had quite a hard time to find something interesting and catchy. Well… since then times have changed drastically and there is not much else to talk about besides the latest pandemic. Probably you have heard enough about it and are desperate to talk about something else. Despite this, I want to elaborate on it a little further, and especially the effect of the corona virus on this special edition of the Ideaal!. Yes, that’s right, this is a special edition of the Ideaal!. It is the first edition to be published solely as a digital version. To let you still feel the authentic reading experience we have given it an entire new look. I know, I know… a digital version will never be the same as the good old fashioned paper edition, but we hope you will all enjoy it anyways! And who knows what we will decide to do when quarantine period is over and we are able to publish paper versions again? Maybe we will keep our new, special looking digital versions to broaden our reader group and send it to Abacus alumni. Or we might even decide, if the digital version is a hit, to make no paper versions at all. After all, it is better for the environment.

Let’s talk about another phenomenon occurring soon. The summer! While I am writing this, the sun is shining through my window and I feel undoubtedly that the summer is coming. With about 20 degrees outside it just screams to go swimming, having a BBQ or reading a book outside. With more than a module to go from this point on it might be a little early to set up our pool but I am sure we await a long and warm summer. At least for me, the weather is given a little positive twist to the entire stay at home situation. While I notice that I broke my promise to not talk about the pandemic again, it lasts me to wish you all good luck with your last module of this year. Hopefully this Ideaal! will remind you of some good old times and brings the warm fuzzy feeling of you and your friends sitting on the Abacus-couch reading the Ideaal!. Stay healthy, save and at home! Carmen

AGENDA • 6 May Candidate Board Announcement • 8 May LIMO 2020 • 11 May Beginning Red Thread Game Hearts with Astatine • 13 May Jackbox • 20 May International Pubquiz

Well, enough about the pandemic and being quarantined for now.

Colophon Editorial address: W.S.G. Abacus Postbus 217, 7500 AE Enschede Phone: 053 - 489 3435 ideaal@abacus.utwente.nl www.abacus.utwente.nl Editors: Emma Donkers Jorg Gortemaker Yanna Kraakman Jitse Kuilman Lavinia Lanting Carmen Tretmans Timon Veurink

Guest writers: Linda ten Klooster (Chairman's Thoughts), Rutger van der Graaf (The Pen) Fleur van Alphen (Your Story), Eline Peeters (Your Story), Vincent Bosboom (Current-Phase relationship for long Dayem bridges), David van der Linden (Review), Stefan Klootwijk (Puzzle Solution), Diana Dalenoord (Interview), Daan Pluister (Puzzle).

Ideaal! is the magazine issue of Wiskundig Studiegenootschap Abacus and the department of Applied Mathematics. The responsibility for the articles published in this magazine lies with the original author(s). The period of notice of Abacus is four weeks before the end of the association year (August 1st). That means that you must cancel your membership before July 4th. If you have forgotten to cancel your membership before that time, you will pay contribution for another college year. Would you like to cancel your membership? Send an email to board@abacus.utwente.nl.

Chairman's Thoughts Text: Linda ten Klooster Dear readers, I have this thing where I connect certain songs to situations or events that have happened in my life. I’m not talking about concerts I visited in the past 20 years, but to stages in my life. Maybe some of you can recognize this if you have these yourself. I think many people have a song they can link to their first heartbreak. For me this was The First Cut is the Deepest by P.P. Arnold (no, not the annoying version of Sheryl Crow). Very cliché, but I still feel like music can help you through some of the harder times, and in hindsight those times will seem less dark. American Pie by Madonna is actually the first song I remember know-

ing, and to this day I remember the clip that belonged to it. As very very small kids this was the favourite song of my older brother and me to dance to in the living room, begging our parents to play it for the 10th time in a row. I believe we even had the clip on video tape – yes, that was still a thing 20 years ago. The artist who reminds me of the first actual festival I went to is Paolo Nutini. In 2015 I went to Lowlands for the first time. I was only 15, and logically wasn’t allowed by my parents to go there by myself, so I joined the friend group of my friends’ older sister. They taught us how it worked at festivals, which bands were worth it to visit, and which weren’t. This is how I got to know Paolo Nutini, and when he performed Iron Sky I was stunned. Unfortunately I haven’t been able to see him live since then, but his

music still makes a great impression on me. The album The Kinks Are the Village Green Preservation Society by the Kinks remind my of all those summer holidays we went to France by car to go camping. The band The Maureens from Utrecht remind me of the time I discovered sometimes Dutch musicians can be talented. I have so many memories of music, which I’m very grateful for. If you have any great songs or tracks to recommend, let me know, I’m always open for suggestions! For now, make some great memories with good music.

The Pen Text: Rutger van der Graaf So here we are, sitting in quarantine. For me, it has really been a change of pace. Normally I have a 1,5 hour train ride, spend my whole day at the university, take a 1,5 hour train ride back home and to finish the day go to soccer practice. Now it is all different. The university decided to continue online teaching until at least June 1st and my soccer competition is finished. Besides the competition being finished, we are also not allowed to practice at the club. This all results in me sitting at home all day. Unfortunately, I am not very good at staying home all day. Especially when I need to study, I get distracted way too quickly. See, normally I would be sitting in the Educafé where everyone can

see me. It is not completely silent since people are talking, and for me, that's a good working environment. Now the tables have been turned. I am all alone sitting in my bedroom trying to study. Since I don’t like to work in silence, I put on some music, and since no one is in my room I start singing along a little bit. Before I know it I am singing songs, looking up different versions of songs, watching random videos on how to play the song whilst I don’t even play an instrument and another hour has passed without doing anything. Luckily for me, there are still conferences where I have to pay attention. But also these don’t go as smoothly as you would hope. Sheets that are normally handed out are now posted online. This shouldn’t be a problem besides the fact that it almost has become a rule that the first link never works. This results in me hav-

ing to wait 15 minutes before the professor can upload the sheet somewhere else on a random spot on Canvas before I can start the assignment. Then when I finally can start, my laptop decides to shut down the whole conference out of nowhere leaving me frustrated. All in all I can say that it has been rough studying at home every day, but I can make it work. I have to make it work because I am stuck at home until at least June 1st. And if I can’t make it work, we are all guaranteed a postponed BSA, so I will try again next year.

Your Story Text: Fleur van Alphen Spring holiday, for me this was the week of relaxing, working, catching up with Valentine's day, and of course Christmas! Relaxing is one of the most important things during a holiday. You can finally rest from all the hard work and studying, so that you feel fresh after this week. However, I didn’t feel like I really needed holiday, I just started studying 2 weeks ago, and before that I had a pretty long holiday. Therefore I decided to at least work two days and earn some money. But with two days gone there was still enough time left for fun things, like Valentine's day. Two very good friends of me and Ruben decided

to celebrate their birthday on Valentine’s Day so that we did not have time for our romances. Therefore we decided to catch up with this during the holidays by spending one full day in the city, lunching, pooling, gaming, dinner and finally having pudding back at home. But that was not the only celebration during the holidays for me. Christmas was celebrated by most people somewhere in the end of December, but why only celebrate this wonderful day once. That way you could only celebrate it with one group of people. We decided this did not make sense, we also wanted to celebrate it together as a house. Therefore, on February 19th, at 19:00, everyone showed up in a nice dress or white shirt (except for the one clown who of course wore a Christmas sweater). The table was

covered in a nice red tablecloth, the first candles of the evening were burning, and Mariah Carey shouted through the room. Me and Ruben made the delicious 'toffe pears', and a soup where two vegetables came together. We weren’t the only ones who tried to make something delicious. Everyone made something special: spooms, salmon bonbons, meat that had to be in a pot for 6 hours on the precise temperature of 160 degrees. Everything was perfect. And we had the nicest conversations. As Rod Wood once song: I wish it could be Christmas everyday.

Your Story Text: Eline Peeters When I was asked to write something about my spring break, I first thought that I would have nothing exciting to mention. After all, my holidays are usually very relaxed and not too adventurous. This basically means I spend way too much time in my room doing nothing (oops?) and once in a while I leave to hang out with friends. However, this holiday I did actually do something worth talking about! During the first few days, my dad and I were busy redoing the wallpaper of my room in Enschede. We initially planned on doing this last June when I moved in, but then we postponed that to the summer break…and then the Christmas break…and then the spring break… but we eventually did it hahah. On Wednesday, my parents, sister, and I went to Katwijk. We made a

short walk around the beach, which we had for ourselves since it was pretty cold and windy. However, after a few minutes we got accompanied by around 100 protesting farmers driving in a long train of tractors across the beach. After that, we went to visit the musical 'Soldaat van Oranje'. We usually don’t go to musicals, but we had heard many good stories about it and were very curious to go ourselves. What makes this musical unique, is the stage that is built in a circle around the audience. After each scene, the platform of the audience rotates to a new set. There’s even a set that is completely outside! Because of their success, it has been extended many times, so you’ll probably be able to visit it once (although corona doesn’t seem to agree).

early for a 3-hour train ride to our jumping competition in Rotterdam. This is always a very fun competition, because you perform in (mixed) teams of 5 people, unlike other individual competitions. It’s all about difficulty, execution, and the pace of consecutive jumpers. In the end, the judges rewarded us with a 2nd place out of 10! Afterwards, we watched the men of the highest level do their crazy double flips with twists, which is always very impressive to see. At the end of the competition day, our association flag and mascot Flippie both had not been 'gebrast', so we peacefully headed back home and enjoyed the last day of the holiday :).

On Friday I went back to Enschede, where I had a high wine with three girls from Linea Recta. We had a very 'gezellige' evening with tasty wines and good food. Then on Saturday morning, I had to wake up

Interview

This time we joined the Stichting Reizende Studenten Abacus (RSA) and talked to Emma Donkers, Daan Pluister, Justus Sleurink, Martijn ter Steege and Wout Leemeijer.

Text: Jorg Gortemaker and Lavinia Lanting

Introduce yourself.

Justus: I am Justus, I am the chairman of the board of RSA and of the study trip. Daan: I am Daan, and I am the treasurer of Stichting RSA and the treasurer of the study trip committee. Emma: Hi, I’m Emma, I am the secretary of RSA and I am the secondary treasurer. Martijn: I am Martijn, I am not in Stichting RSA, neither do I have a function in the committee, but I am part of the subcommittee acquisition. Justus: Of the study trip committee of the Stichting RSA. Wout: I’m Wout, I am part of the acquisition subcommittee of the study trip committee of Stichting RSA and I am also part of the logistics subcommittee of the study trip committee of Stichting RSA.

What is the Stichting RSA exactly? What does it do?

Justus: The 'stichting' (foundation) mainly organizes the study trip, we don’t have that many meetings. Daan: And we have a “Raad van toezicht” and we have a “Kasco” committee. Martijn: Auditing committee and Supervisory Board.

Justus: But that’s about it for Stichting RSA and we’re just separate from Abacus, so that Abacus cannot be held responsible if we fail financially.

Emma: I wanted to go on the study trip, almost no one was organizing it, so I decided to help organize it. Justus: Mostly everyone's reason. Martijn: My inspiration were the vlogs of Jasper.

What is the difference between the board and the committee? What is the research question leading the study trip? Justus: Stichting RSA has a board to be separate from Abacus and it is necessary for a foundation, and the committee is like any other committee of Abacus. Daan: We make it too clear now. Justus: Oh shit! Emma: There needs to be confusion. Justus: How can we add more confusion? Daan: We don’t have members. Martijn: We are a non-profit organisation (“That is already included in the “stichting””), yeah but just for the confusion, uh, for clarification I mean. Justus: Even though “stichting” RSA does not have members, the study trip committee of “stichting” RSA does have members.

Wout: New technologies implemented in daily life in Russia. Emma: As broad as humanly possible.

How did you come up with this research question and why?

Emma: We wanted something broad, in Russia there’s a lot of very different companies close together, especially in the cities that we’re visiting which are Saint Petersburg and Moscow. And we don’t want to have to travel miles and miles and miles, just to find a company that fits our question. Justus: We also don’t want to have to search for hours and hours, just to find one company that fits our research question to visit, because we need to have enough visits. Daan: This answer is too honest.

What made you want to join Why did you guys pick Moscow RSA? or Russia in general?

Wout: Cheap vodka. That’s the main reason. Justus: We came up with some ideas of where to go. Daan: And then we wrote down some pros and cons and then we had a voting round. What was the second candidate? Emma: Argentina/Brazil or Italy.

Emma: In a few lessons I will be able to count and then we can combine our skills. Daan: I only know Daan in Russian. Martijn: Njet (in Russian). Daan: I know what book is in Russian.

Do you feel you work well as a team?

What is interesting about this Emma: As a board we don’t do anylocation? thing. But the committee works Martijn: Vodka. Wout: Quite different country than the Netherlands. Martijn: It is a country in both Europe and Asia. Emma: But we are only going to the European part. Martijn: I don’t see a problem there. Emma: There’s just a lot of history and culture there, so it’s also simply an interesting country to visit. But there are also a lot of, like I said, divers companies.

How are your Russian skills coming along in preparation to this?

Justus: I haven’t started. Emma: I have a 62 streak in Duolingo Wout: I can order vodka in Russian. Martijn: But can you only order two? Wout: Yes. Martijn: So if you do that 3 times, then we all have vodka for the six of us.

well. Justus: Not that we don’t work as a team, we just don’t really do anything.

Martijn: It’s a solid maybe.

What will you be looking forward to?

Martijn: Drinking vodka. Wout: Watching The Netherlands become European champions. Emma: I will enjoy seeing the sights and also experiencing a very different culture. Daan: I am excited to see the Moscow Metro. Justus: * looks it up *, I think I am looking forward to the Moscow Metro now as well now.

Who would survive the best and who would get by the worst in Russia? Why?

Emma: Mariya would survive the best. Because of obvious reasons. Martijn: Fleur would be fine, because she is miss worldwide. Wout would probably not survive because he would only drink vodka and do nothing else.

Promote the Study Trip.

Martijn: It’s nice. Justus: People can’t join this study trip anymore, but we can promote joining RSA for next year. Even though people cannot join this trip anymore, I’m sure people will want to join in 2 years. Martijn: It’s fun. Emma: And you get ECs, probably.

Puzzle: CZ€OOMMXIX Text: Timon Veurink This puzzle is going to be very hard, but you’re in luck! I can send you right away to someone who knows the answer to this puzzle. So you can check your answer right after you’re done. Just ask the 20th president of the United States, his veterinarian, who won an award, where the award for best actor (25th edition) went to someone

whose family member was the villain in a Disney movie from 2010, starring a guy with a song made by a scientist who won a Nobel prize with someone who in 1925 also won an award, named after someone whose roses, their 5th uncle had someone working for him with his interior relations, his father.

The puzzle: What was Frigyes Karinthy the first proponent of in 1929?

Just Abacus things...

On the Couch Text: Jorg Gortemaker, Lavinia Lanting

1. Introduce yourself! J: I am Jorn and I am sitting on the couch. There isn’t much else to say. T: I am Thomas and I’m in my first year. L: I am Leon, I am 18 years old. 2. Is everybody sitting on a couch? L: No, I am sitting on a chair. 3. How long have you been on the couch? L: 30 minutes. J: Yeah, I guess about that long. T: 10 minutes. 4. How long has it been since the last time you went outside? L: I went out this afternoon. T: I went out this morning to deliver newspapers. L: Oh yes, a vital job. J: About 30 minutes plus 10 minutes. 5. Who do you prefer to sit on the couch with most? J: With people who want to play card games. T: With Leon and a bag of chips. L: With Thomas and a Torondo. 6. What is your favorite article in the Ideaal!? T: The memes of course! L: Yes, obviously the memes. J: Why not the puzzles, guys? The puzzles are obviously better. T: The memes from the Lustrum Edition were the most fun. Or perhaps

my own article was. L: Can I change my answer? The article that Thomas wrote is my favourite. 7. What was the highlight of your day? T: The project meeting. It was really interesting. L: Sleeping was the highlight of my day. J: Yeah...I ate an agg. My day wasn’t that special. 8. What did you learn to cook, now that you have the time to experiment and practice? J: Absolutely nothing. T: I still have not cooked a single thing. 9. What is your favorite math theorem? T: Fermat’s Great Theorem. L: The Pythagorean Theorem! It has lots of practical uses. J: I like the fact that 33+44+33+55 is equal to 3435. 10. Are you a cat or a dog person? L: Dog! Obviously dog. Cats can be funny sometimes. J: They’re both nice. T: Neither! 11. Cayley or Hamilton? J: Cayley of course. T: Hamilton, because he is obviously better. L: I’ll just go for Hamilton.

12. What did you eat tonight? L: I almost forgot about having had dinner. I had salad with chicken and fries. T: I had tasty pasta. J: Super delicious burritos according to my grandma’s recipe, but then not according to my grandmother’s recipe. 13. What are you going to do next? T: I’m going to draw. L: You guys already saw how well I can draw. J: I’m going to play chess with Erik, such that we are exactly done before the drawing activity.

Current-Phase relationship for long Dayem bridges Text: Vincent Bosboom To distract you from all the mathematics you are being confronted with every day, I will here tell you something about something completely different: physics (which is of course just mathematics in disguise). The physics I will tell about focuses on very very small structures of just several nanometers in size called Dayem bridges. A Dayem bridge is made by taking a very small piece of superconducting material and creating a constriction in the middle by for example varying the thickness or width of this superconductor (see figure). When this bridge is small enough a strange effect called the Josephson effect will occur; One can measure that in this bridge there will be a oscillating current which occurs without giving rise to any resistance. This current depends sinusoidally on the phases of the quantum mechanical wavefunction at the two sides of the bridge given by the current phase relationship (CPR): This might seem like a very abstract and unimportant effect, but it actually has many useful applications. It is for example used in making very accurate magnetometers

and it seems to be very suitable for making qubits for quantum computers. In reality the CPR of a Dayem bridge is not always sinusoidal but varies also as a function of the length and width of the bridge. In general the behavior of a Dayem bridge can be described mathematically by a system of coupled partially differential equations called the GinzburgLandau equations:

In these equations Ψ is the order parameter, which can loosely be seen as a measure of the strength of the superconductivity at a certain point. A is the (for you all of course well known) vector potential and κ is some material parameter. An analytical solution of these equations is not possible, so one has to resort to numerical solutions. Because the geometries of these Dayem bridges can be quite complicated a finite element method is the most suitable numerical solution method because it very suitable for describing these complex geometries. The GinzburgLandau equations can be solved by using a finite element method with linear element for Ψ and Nédelec elements for A. The current phase relationship for different bridge lengths can then be calculated as shown in the figure.

eventually at some critical length it even becomes multivalued. At this point a process called phase-slip will occur which can cause resistance, thus destroying the perfect conductivity of the bridge. If the dimensions of the bridge are increased even more at some parts of the bridge the superconductivity can be lost and one might observe a lattice of so-called Abrikosov vortices inside the bridge, where the superconducting material has returned to the normal state again. When physicists fabricate these kind of bridges for either magnetometers or qubits, it is important for them to know their exact properties. Small differences in the manufacturing procedure and the bridge parameters can result in completely different behavior. Therefore we as mathematicians with our knowledge of modeling can be very useful during the process of designing the squid and testing its properties.

Here we see a strange thing happen. As the bridge length increases the CPR becomes less sinusoidal and

Review: E.S.B.V. Buitenwesten Text: David van der Linden I've been asked to write a bit about the student boxing association "Buitenwesten". During my Kick-In I collected lots of brochures of sports associations and signed up for even more email lists. During the first few weeks I was trying out a new sport almost every working day. I had already tried out a couple of sports before i went to the boxing training. But after I went to the open boxing training I felt like I didn't need to check out more sports anymore. If you don't want to do any sparring (yet), then you can just come to the beginners trainings. You'll get to know the boxing techniques, like

pushing, dodging and moving, and most of all you'll get really exhausted from doing boxing fitness and pushing on the bags or gloves of a partner. Boxing fitness is a big part of the trainings at "Buitenwesten". And the great thing about boxing fitness is that a lot of those exercises can be done at home. During this Corona period I've been boxing at home 2 times a week. A common misconception is that boxing causes a lot of injuries. But in reality injuries from training are really rare. The dangers of boxing lie in the competitions but unlike with other sports its not normal to do those every week.

After having done a training I feel really well and I can recommend everyone to try out a training during the introduction periods or after sending the board an email. For more information go to https:// buitenwesten.utwente.nl/ Or email bestuur@buitenwesten. utwente.nl

Puzzle Solution: Cutting Cake Text: Stefan Klootwijk We will use some analytical geometry to solve this problem. Let’s start by defining some points in such a way that we can easily describe what’s going on. The half circle has two corner points, which we call A and B. Moreover, we draw our coordinate system in such a way that A = ( -1 , 0 ) and B = ( 1 , 0 ). It should be obvious that the cut intersects both the line AB and the circular arc. We denote these intersection points respectively as K and C, where we assume w.l.o.g. that K is between A and O (see the first figure).

The circular plate on which we want to fit the two pieces of cake should pass through the points B, C and K (the blue circle in the second figure).

noted as H, i.e., H is the unique point on AB between K and B such that |CK|=|KH|. Moreover, the new position of the point A will be denoted as E (see the third figure).

An important observation is to see that the triangle KCB must be an isosceles triangle with |CK|=|CB| in order to optimally cover the circular plate (a formal proof of this observation is left as an exercise to the reader). This observation allows us to say that C = ( x , √(1-x²) ) and K = ( 2x-1 , 0 ) for some x. The smaller piece of the cake (with points C, A and K) can now be relocated in such a way that its (original) point C will be placed at point K, and its (original) point K will be on the line AB (between O and B). This new position for K will be de-

It should come as no surprise that for the optimal cut this point E also is on the blue circle. It remains to determine the coordinates of E in terms of x and to find the value of x such that |EZ|=|CZ|, where Z denotes the centre of the blue circle (see the fourth figure).

To find the y-coordinate of Z, we use

to derive

For the first task, we can derive that |CB| = √(2-2x) and use |CB|=|CK|=|HK| to derive that the coordinates of H are given by

Now let D and F denote the orthogonal projections of respectively C and E on the line AB. The reader should be able to verify that the triangles EFH and CDB are similar, i.e., we have

Moreover, we have |EH| = |AK| = 2x and |EH|² = |EF|² + |HF|². From this system of equations we can derive that |EF| = x√(2+2x) and |HF| = x√(2-2x). Hence, the coordinates of E are given by

In the meantime, the reader should be able to verify that the diameter of the blue circle (in terms of x) is given by

is approximately 1.6558… So, starting with half a circle of (original) diameter 2, we can put in on a plate of diameter at least 1.6558… Therefore, the remaining half of the pie in the original question (of diameter 24 centimeter) can be fitted on a plate of diameter 19.87… centimeter when cut in two pieces, but not on a smaller plate. In particular, it is possible to fit the two pieces on a plate of diameter 20 centimeter.

Finally, we’ll find x by solving |EZ|²=|CZ|². This yields the following (terrible looking) equation:

This equation can be simplified to There is only one solution to this quintic equation with 0≤x≤1, namely x ≈ 0.1866… The corresponding (optimal) diameter of the blue circle

Puzzle Solution Text: Timon Veurink To solve this puzzle, you need to look on the Wikipedia page of all the astrological body’s. From each article you need to take the character equivalent to the amount of moves you had to make. Watch out for spiders means you should look on the web, and /’Butdon’tcountonit/ means that you should not count the part between backslashes on the pages. But you do count spaces as characters.

It is also an actual route, but that doesn’t matter for the solution.

The twenty-third character of Pollux’s page is R.

The twenty-third character of Neptune’s page is A. The twenty-second character of Saturn’s page is L. The fifth character of Jupiter’s page is T. The second character of Castor’s page is A. The fourteenth (4 teeny) character of Sirius’ page is I.

If you google Altair, you’ll see it is another star, and you know you solved the puzzle.

Interview: Femke Woudstra and Sjoerd Gallmann Text: Diana Dalenoord 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.

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

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 entail? 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, be-

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".

sides 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

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 checkout 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!"

Meme Page

Puzzle: Nonogram Text: Lavinia Lanting Can you solve this nonogram and discover which committee is here represented?

Puzzle: Geoguesser sudoku Text: Daan Pluister In this puzzle, the regular sudoku rules apply. The pictures below and on the next pages are numbered. Find their location on the map and fill in the number there. Good luck!

Colour-In

Interview: Nelly Litvak Text: Diana Dalenoord 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 sheâ&#x20AC;&#x2122;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 circumÂ stances 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.â&#x20AC;? 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, Eurandom. 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.

ence, 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."

What do you want to advice your female students? Nelly: "Don't perpetuate the oldfashioned image of women in sci-

Dear readers... Text: Jorg Gortemaker and Lavinia Lanting Dear readers of the Ideaal!, for the next edition of the Ideaal! we would love to see what you would like to share with the rest of Abacus. Because of the current situation it is rather difficult to make the Ideaal! that you're used to. Pictures of

the activities and of the members of our beloved association are difficult to come by and pieces such as "A Day With..." can no longer be written. So for the next edition we would like to see a lot of your puzzles, photos and memes to make the next Ideaal! one of the fullest yet! Do you have pictures of yourself or of something you did that you would like to share? Or would you like to gift your fellow mathematicians with a laugh by sending a meme or to challenge them with a delightful puzzle? Then please, send us whatever it is you would like to see

appear in the coming online edition of the Ideaal!. Of course other pieces are also very welcome. Hopefully we will see a lot of pieces sent in to create something for all members of Abacus to aid in avoiding the boredom that probably will come as long as the situation will be as it currently is. Sincerely, your Ideaal! committee

Whatâ&#x20AC;&#x2122;s a collector mirror? Book and customize your ASML excursion to find out Do you study physics, computer science, mathematics or nanotechnology? Get to know us and get inspired. Sign up before April 30 at asml.com/excursions 24

Thursday

May 14 2020 13:30 - 19:30