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MASTER’S MAGAZINE UTRECHT GRADUATE SCHOOL OF NATURAL SCIENCES # 2 [ 0 9 - 2 0 1 0 ]

Natural

Working in research: CERN - where worlds collide

Study abroad: testing the water in Pretoria

Thesis research: comparison of stochastic models


Graduate School of Natural Talented Master’s and PhD students at the Utrecht Graduate School of Natural Sciences (GSNS) acquire the knowledge, skills and insight needed to hold top positions around the world, including those in research. Graduates receive a sound academic training, completely taught in English, and gain an excellent understanding of the role played by the natural sciences in contemporary society. The GSNS provides a thorough fundamental scientific education, which you can adapt to your own needs by choosing specific courses and research subjects. Some of our Master’s programmes, such as Game and Media Technology as well as Meteorology, Physical Oceanography and Climate, are unique worldwide.

table of contents

Each year we organise several summer schools, at which we teach topics related to our Master’s programmes. The Graduate School also facilitates incoming Master’s student exchanges within the context of the Erasmus programme. Participating in a summer school or an exchange programme is a great opportunity to

get to know our educational philosophy, and the open, professional atmosphere here at the university and in the city of Utrecht. All Utrecht Master’s programmes that include mathematics, information and computer sciences, physics, and chemistry are taught within the GSNS. In order to ensure a high level of research in an international environment, we combine cutting-edge research with academic skills in our training, much of which is multidisciplinary. In addition, we also supply some professional Master’s programmes connecting science and society.

2 Graduate School of Natural Sciences 3 Events 4 Avalanche formation and prediction models Meteorology, Physical Oceanography and Climate 6 Choices in Information and Computer Sciences Business Informatics, Computing Science, Game and Media Technology, Technical Artificial Intelligence 8 Choosing the right Master’s programme History and Philosophy in Science 9 Science provides the basis for solutions Scientific Computing 10 Working for the world’s smallest zoo Science Education and Communication 12 Unexpectedly ending up in sustainability NanoMaterials: Chemistry and Physics

2 it’s only Natural Utrecht University [09-2010]


Events

Sciences

April 2010-April 2011

Master the Universe! Exhibition on the search for “a theory of everything” www.mastertheuniverse.nl 7 October 2010

Master’s Information Evening www.uu.nl 24 November 2010

Hyperience symposium on High Performance Computing www.a-eskwadraat.nl/Activiteiten In Utrecht we combine research and education in a natural way. All GSNS Master’s programmes are firmly embedded in renowned Utrecht research institutes, which are equipped with modern facilities. The eight institutes and the Graduate School offer Master’s and PhD students a stimulating environment in which to work, including contacts with top-class researchers such as Nobel Prize winning physicist Professor Gerard ’t Hooft. All GSNS Master’s programmes are illustrated in this magazine by personal experiences. 

18 February 2010

Master’s Information Evening www.uu.nl 3 maart 2011

PAC symposium - annual symposium for Chemistry students http://pacsymposium.nl/ 26 March 2011

Dies Natalis – 375 years Utrecht University www.uu.nl

14 News 15 Motivation for pro active participation Astrophysics and Space Research 16 Testing the water in Pretoria Energy Science 18 A national maths curriculum with international attraction Mathematical Sciences 20 Springboard to a career in business Science and Business Management 21 CERN: where worlds collide Particle Physics 22 Fundamentals for choosing Theoretical Physics Theoretical Physcis 24 Comparison of stochastic models Stochastics and Financial Mathematics 26 Summerschools in Science 27 Colophon 28 Master’s programmes and entrance requirements [09-2010] Utrecht University it’s only Natural 3


Master’s programme: Meteorology, Physical Oceanography and Climate Subject: Thesis research

Name: Malou Maris Age: 24 BSc: Physics At: Free University, Amsterdam

Avalanche prediction Malou Maris spent eight months in the French mountains to model the climate of the Pyrenees and its development. She used 50 years of collected data for this. Her conclusion is that although the mountains are heating up, they are not becoming more dry or wet.

“There is more to avalanche risks than snow thickness. Very cold, dry, powdery snow increases the risk of slippery situations and snow displacement. When the snow starts to melt it becomes more wet, and the risk of avalanches decreases until large ice balls are formed. When dry snow drops on that unstable subsurface, chances are high that the snow will start slipping, and the whole package comes down. That is why not only the amount of snow is being measured by area managers.”

Since the Pyrenees cover the complete FrenchSpanish border from east to west and border both the Atlantic Ocean and the Mediterranean Sea, a very diverse climate and precipitation pattern can be found in the mountains. The French side, connected to the ocean, is wet and cold due to the northwestern wind. The Spanish side is more dry and warm, except for the eastern part. This is due to the wind changing at times to south-east, where the Mediterranean Sea is situated.

Malou Maris speaks about the process of snowfall and avalanche formation with clear signs of knowledge. She performed her thesis research of eight months studying the Pyrenees, the mountain area separating France and Spain. As a Master’s student in Meteorology, Physical Oceanography & Climate, she arranged a placement at the French snow research institute in Grenoble, France. That village is situated in the Alps, not the Pyrenees. But all snow, precipitation and temperature data collected in French mountains is processed at this institute. Fifty years of data, from 1958 until 2008, awaited for her when she arrived. Malou’s job was to prepare all these data to fit in an existing model and run it. The model describes the development of the climate during this time period and its consequences for the local environment of the Pyrenees.

Culture clash

ch an advanced “Nobody had put su l before, for view on this materia chance to apply od go a as w it ou al M ath and modeling in her knowledge of m reality.”

4 it’s only Natural Utrecht University [09-2010]

Malou arrived with the ambition to map all these different influential factors. However, her supervisors held a different view. “My internship started with a misunderstanding. The French supposed I would only analyze their data, while I intended to study both the French and Spanish situation.” At first she could do nothing but obey, but after a while Malou convinced her supervisors that she could easily do both, because using English literature saved her a lot of time compared to using exclusively French literature, as they tend to do in Grenoble. “Unfortunately at that time it was already too late to finish the Spanish part.” Malou used data of temperature, snow heights, precipitation and snow days based on data collected at the weather stations in the Pyrenees, with French data from 1958 until 2008 and – because of time constraints - Spanish data from 1970 until 1990. Nobody had put such an advanced view on this material before, and for Malou it was a good chance to apply her knowledge of math and modelling in reality. By using several different calculations and perspectives, she showed that indeed the temperature rose during these 50 years, with an average of 0.25 degrees Celsius per decade. Furthermore, she found a


formation and models breakpoint in 1981, at which the temperature shifted from a decreasingly warming to an increasingly warming trend. Remarkably, this temperature rise did not change precipitation significantly. It only shortened the ‘snow season’ with a couple of days. These trends are true for the whole area, but Malou found differences between sub-areas as well. “Every mountain has its own weather.”

Rain gauge

happens when they are not: “One afternoon a pretty touristic village was plumped upon by an unpredicted avalanche. Panic arose, and although luckily no one was hurt, it was quite a shock to the tourists and locals. It turned out later that wrong measurements were used in the model which had disrupted the calculations.” 

“We wanted the m odel to represent the ma jority of the data , not some extrem e situ

Modelling sounds easier than it actually was with all the collected data, tells Malou. “The database contained quite some unreliable data, as a result of forgotten or poorly preserved input. For example, in case of heavy snowfall or low frequency measurements, the rain gauges overflowed. That is why we noted an underestimation of the precipitation based on our model. When we compared our values to the actual snow height, it sometimes even differed a whole meter. We had to correct for that.”

On top of these irregularities, the collecting efforts of some stations turned out to result in quite remarkable measurements. Malou: “We decided to remove these outliers, even though we realized these might have been valid and valuable data. But we wanted the model to represent the majority of the data, not a few extreme situations.” A slightly shorter skiing season but no change in snowfall nor a shrinking skiing area is quite good news for winter tourists. But what will the impact of temperature increase mean for the natural environment? “That is unclear at the moment. We did not find any direct effects on humidity, no increase in mudflows. I assume plants and animals will only have to adjust to the rising temperature itself, not to any other factors.”

ations."

Master’s programme: Meteorology, Physical Oceanography and Climate URL: • www.uu.nl/programmes/mpoc for international students • www.uu.nl/masters/mpoc for Dutch students Contact: Dr Aarnout van Delden a.j.vandelden@uu.nl +31 (30) 253 3168

Malou’s data are now processed and will indirectly be applied in the avalanche prediction models Grenoble is using. These models are already very precise, in Malou’s experience. In fact, she experienced what

[09-2010] Utrecht University it’s only Natural 5


Master’s programmes: Information Technologies in Science and Society Subject: Four related programmes

Choices in Information and Main concern: Strategic deployment of ICT in business processes Thematic focus: Organisation and information, Business/ IT alignment, Software product management, Chain automation, E‑commerce Core courses: E-business, Enterprise architecture, Method Engineering and Knowledge management Graduation profiles: Researcher, Business consultant, ICT consultant and Software Entrepreneur Master’s thesis example: Performance measuring in communities of practice (Mark van der Meijden) Although discussed by several authors, there is no a general method that can be used to efficiently implement knowledge management interventions. In this research a method is developed that (1) provides advice about which knowledge management interventions should be implemented, and (2) measures the value of that implementation. The advice is based on a knowledge network analysis combined with the usage of current knowledge management facilities. The measuring method gives a good indication of how a community of practice is functioning at a certain moment. The method is validated by a case study but more validation is needed. Utrecht Excellence Scholarship: As a Business Informatics student you may receive an Utrecht Excellence Scholarship. Only the most promising candidates showing the highest achievements may receive a scholarship. Selected students are awarded a scholarship between 1,500 and 26,950 euro per year. It is not possible to apply for the Utrecht Excellence Scholarship. 

Master’s programme: Business Informatics URL: • www.uu.nl/programmes/busi for international students • www.uu.nl/masters/busi for Dutch students Contact: Dr Rik Bos +31 (30) 253 9757 mbi@cs.uu.nl 6 it’s only Natural Utrecht University [09-2010]

“We have weekly colloquia at which students, teachers and sometimes representatives of companies share many ideas. Students and teachers have lunch together afterwards.” (Vali Georgescul)

Computing Sciences

Business Informatics

“I chose Business Informatics in Utrecht because of personal recommendations, the broad range of subjects and its high ranking in international league tables.” (Ömer Aydinli)

Main concern: Development of modern information and software system concepts, analysis techniques, and design methods Thematic focus: Software design, Formal methods and program analysis, Algorithm design and complexity, Advanced planning and decision making, Decision support systems and their realization, and Algorithmic data analysis Core courses: Each student completes five core courses, depending on the thematic focus chosen Graduation profiles: Researcher, Software designer and Software Entrepreneur Master’s thesis example: RFID - Threat Taxonomies & Improved Anonymity for Hash-Trees (Michael Beye) RFID (radio frequency identification) is an increasingly popular technology used in ePassports, the OVchipcard, clothing tags, etc. As any identification method, it suffers from attacks that violate privacy and security. This thesis provides a checklist to assess the properties, demands and risks of RFID systems in a structured way, based on a taxonomy we designed to organize possible threats and their defenses. Authentication protocols, used to verify the claimed identity, often make use of hash trees. This thesis proposes an alternative tree structure and associated algorithm and improves upon existing research. 

Master’s programme: Computing Sciences URL: • www.uu.nl/programmes/ computingscience for international students • www.uu.nl/masters/computingscience for Dutch students Contact: Dr Ad Feelders +31 (30) 253 3176 science.acs@uu.nl


When you’re interested in the field of Information and Computing Science you do have many Master’s programmes to choose from. At Utrecht University Master’s students get the chance to look across borders of their discipline and take courses from related programmes in their individual study path. In which programme will you enrol? Here’s a survey of the similarities and the specifications within these four programmes.

Computer Science Main concern: Modelling virtual worlds, creating characters and convincing behaviour, focusing on the technological aspects Thematic focus: Game design, Modelling, Pattern recognition, Image processing, Computer vision and multimedia, Geometric computing Core courses: Each student completes at least four of twelve selected courses Graduation profiles: Researcher, Game developer, ICT consultant and Software Entrepreneur Master’s thesis example: Rendering large environments in game related applications (Rogier Saarloos) This thesis concerns the possibilities of creating credible environments in game related applications by using advanced terrain rendering algorithms. These algorithms are commonly derived of GIS (Geographic Information Systems) research. Two techniques, primarily using the CPU and GPU, were compared for implementation complexity, performance and use of the terrain rendering concepts called geometry clip maps. These two techniques are tested with simple as well as brute rendering techniques. The brute methods provide more quality, are easier to implement, and to adapt in order to fit into a game related application. 

Master’s programme: Game and Media Technology URL: • www.uu.nl/programmes/gmt for international students • www.uu.nl/masters/gmt for Dutch students Contact: Dr Hans Philippi +31 (30) 253 2819 science.gmt@uu.nl

“I not only learned about theoretical models and philosophical questions related to Artificial Intelligence – I also did many interesting practical things.” (Berend Kemperman)

Technical Artificial Intelligence

Game and Media Technology

“The technology that is studied here has a very exciting range of applications. Analyzing sound files, animation of 3D human models, and 3D reconstruction of objects through photos are just a few examples.” (Pascal van Beek)

• Two-year teaching programme in English • International environment • Opportunity to tailor your own study programme • Personal supervision and friendly atmosphere • Thesis research project during eight months

Main concern: Development of intelligent software, using multi agent systems, machine learning, knowledge discovery, and cognitive robotics. Thematic focus: Multi agent systems, Agent programming, Argumentation, Games Core courses: Intelligent Agents, Multi agent systems Graduation profiles: Researcher, ICT consultant and Software Entrepreneur. Master’s thesis example: Effectiveness in Actor-Agent Teams: An Experimental Study on Team Performance in a Simulated Crisis Environment (Marten Kampman) These experiments are processed integrating both agents and humans in a team as equal members. A software platform facilitates team coordination, actor-agent communication in natural language and allows agents the same capabilities as humans. Crisis scenarios are developed for the simulation environment to compare team performance and effectiveness of human only teams and actor-agent teams. By comparison, the results show neither large decrement, nor large increment in performance. This is mostly due to the current level of agent complexity. Improvements are needed in communication capabilities and team oriented helpful behaviour. 

Master’s programme: Technical Artificial Intelligence URL: • www.uu.nl/programmes/atech for international students • www.uu.nl/masters/atech for Dutch students Contact: Dr Henry Prakken +31 (0)30 253 23 13 science.at@uu.nl [09-2010] Utrecht University it’s only Natural 7


Master’s programme: History and Philosophy of Science Subject: Choosing the right Master’s programme

Choosing the right Master’s programme Name: Femke Kuiling Age: 35 BSc: Physics (and Art school before that) At: Utrecht University

Finding out which Master’s programme will suit you is a difficult task. A good orientation takes time and effort. Femke Kuiling knows all about that. The History and Philosophy of Science student took quite an adventurous detour to come where she’s at now. Femke initially started at an art school after finishing her high school. “I had always been wondering whether the world actually is what we think it is, or whether our perception plays tricks on us. In the art school I learned a lot about how you can look at the world in various ways. In the end though the actual creation and selling of art didn’t suit me as much I thought it would.”

Master’s programme: History and Philosophy of Science URL: • www.uu.nl/programmes/hps for international students • www.uu.nl/masters/hps for Dutch students Contact: Dr Lodewijk Palm +31 (30) 253 8283 l.c.palm@uu.nl 8 it’s only Natural Utrecht University [09-2010]

Six steps towards a well-considered choice 1. Be aware that a Master’s programme is different from a Bachelor’s. 2. Take a good look around to see which options are available. 3. Talk to people in the programmes you are considering, to get an idea of what the programme is like. 4. Start looking for a Master’s programme in time, so you can tweak your Bachelor’s if necessary. 5. Visit seminars at different research groups, in order to get a realistic impression. 6. Weigh both career perspective and personal preference in your decision.

Gaining insight After a period of, among other things, living and working in Iceland, Femke started a Physics Bachelor’s in Utrecht: “I thought I would get a deeper, fundamental, insight in existential questions, but there was too much emphasis on calculations for my taste, although I liked the practical classes. The courses that really fuelled my imagination however, were the philosophy of science courses.”

Two options Femke felt that her preferences left her with two options: doing the Master’s programme Particle Physics or enrolling in History and Philosophy of Science. “In choosing courses for my Bachelor’s, I had always taken into account the possibility of an experimental Master’s programme. I had assisted with experiments and talked to someone in the programme of my preference. I basically asked him what he did on a day-to-day basis, to see if I could do that. I also attended seminars of the different research groups that gave me insight into the various programmes.”

Choosing Two things inspired Femke’s final decision, she explains: “First, when talking to people from Particle Physics, I found out competition over PhD positions was quite fierce. I learnt I would have a disadvantage because I’m ten years older than the average student. Secondly, I decided that I should do what I really enjoyed; pondering science's big riddles.” 


Master’s programme: Scientific Computing Subject: Working as a professional

Jeroen van Grondelle works at Be Informed, a software supplier that provides infrastructures for businesses, with which to record and manage their knowledge. His job Name: Jeroen van Grondelle Age: 35 BSc: Mathematics At: Utrecht University

is to match the latest ideas in scientific modeling to the product portfolio. In a dynamic field of work that requires intensive knowledge, Jeroen’s background in Scientific Computing gives him a real edge, he explains.

Science provides the basis for solutions “After my graduation I had several jobs in IT, developing applications that supported knowledge workers”, Jeroen says. “Their apps typically focus on the processes and provide little support in the most important part of their work: the decision making. As these apps are developed by software engineers and difficult to change, it is hard to keep up with the demands of an ever changing working environment.”

Conceptual overlap So Jeroen asked himself a question: how can an owner of knowledge - say, an insurance underwriter - capture his knowledge in a form that is much closer to his everyday work? And how can we solve this in a way that can be applied generically? “That’s why I’ve always been searching for the conceptual overlap in the different projects I executed”, says Jeroen.

Universal models Jeroen found this common ground in scientific models, not unlike the ones he used as a student in Scientific Computing. Jeroen: “For example, I’ve been involved in the automation of a lot of decision making processes, be it for subsidies, insurance claims or permits. Basically they’re very much alike. The basic questions are: are you entitled to it? And if so: what do you get? When you take out the specifics, you get a fairly universal decision making model.”

Drawing on science skills Although Jeroen reckons Scientific Computing can get quite abstract, he does make use of the knowledge and skills from the programme in his present job. Jeroen: “I’ve been trained to envisage abstract situations and think them through before I actually apply them to a real world situation. And I did my thesis research on algorithms design: large scale calculations similar to the ones I use now.”

Springboard A research Master’s degree can be a great springboard for a career in business, Jeroen believes: “Working in a professional business environment can be a bit of a culture shock, but there are ways to prepare yourself. For example, I did a group project in my second year and learnt useful skills by involving in various student activities. But it has been the Scientific Computing programme that has proven to be most valuable. After all, it’s science that provides the basis for the solutions my company supplies.” 

specifics ”When you take out the decision you get a fairly universal making model.”

Master’s programme: Scientific Computing URL: • www.uu.nl/programmes/scicomp for international students • www.uu.nl/masters/scicomp for Dutch students Contact: Prof Rob Bisseling +31 (30) 253 1481 r.h.bisseling@uu.nl

[09-2010] Utrecht University it’s only Natural 9


Master’s programme: Science Education and Communication Subject: External thesis research

Working for the world’s smallest zoo Name: Marjolein Schrauwen Age: 24 BSc: Biology At: Utrecht University

Marjolein Schrauwen, student

“Positions for external theses are posted on our university blackboard. The Artis vacancy caught my eye. Of course part of the attraction was the romantic notion of working in a zoo. But more important, the research itself appealed to me. Artis is preparing a permanent exhibition on microbes; the Micro Zoo. For this purpose, I looked into the public’s view of microbes, together with a fellow student. In addition, I would actually prepare texts for the information panels at the exhibition. I liked that combination of sociological research and writing.”

things "It was kind of exciting to do g a for a first time, without havin margin for errors"

For real “I worked at the Artis educations department. My supervisors were there when I needed them, but during my daily work they gave me room to find out things for myself. That worked really well for me, although working in a professional environment was new to me. It was kind of exciting to do things for a first time, without having a margin for errors. After all, my research results would influence the appearance of this exhibition.”

Valuable experience “Apart from the research results, I produced a preliminary education plan for the new exhibition and a prototype of a content screen that’s going to be used to provide visitors with information. It’s not as much development work as I had hoped in advance, but I’m still very pleased with how my research turned out. Working in an organization like this is a valuable experience, and I developed my research skills considerably.”

Best of both worlds “I would probably be perfectly happy as a developer of content for exhibitions and for educational purposes. And for my next internship I’m returning to Artis, but for a very different kind of research, in behavioural biology. My ambition would be to combine these two fields of work, but at the moment I don’t know how I could. For now I’m enjoying both.”

10 it’s only Natural Utrecht University [09-2010]


Science Education and Communication student Marjolein Schrauwen found a position for her external thesis that probably tickles everyone’s imagination:Artis Zoo in Amsterdam. For a new permanent exhibition she researched the public’s attitude towards the subject microbes.

“Marjolein’s internship was divided into two parts. The product development she was going to do is a prime example of science communication, as it involved writing about a rather complex subject for a wide audience. Her sociological research is something lots of organizations seek in our students. For them it’s a cost efficient way to tap into a vast reservoir of knowledge, for the students it’s a valuable real world work experience.”

Learning goals “As her supervisor, I formulated Marjolein’s learning goals with her before she started her internship. One of the skills Marjolein wanted to improve was layered writing for different audiences with different knowledge levels. In that respect it’s a pity that she didn’t spend more time to do so.”

Name: Liesbeth de Bakker Age: 40 Education: MSc Biology and a PG course Science Communication At: Leiden University and Imperial College London

Liesbeth de Bakker, Utrecht University supervisor Flexible work “The flexibility of the labour market is not necessarily a bad thing. I often see graduates do a couple of projects and then finding work as an educational assistant. Our graduates can be found anywhere where knowledge is translated to be more practically applied. That variety in subject matter is a very appealing aspect of the programme.” 

“As her supervisor, I formulate d Marjolein’s learning goal s with her bef ore she started her internship."

Plenty of choice “Zoos, museums and the like are always looking for students from the Master’s programme Science Education and Communication. The number of vacancies is far greater than the number of students at any given time. That’s obviously a comforting thought. You have to realise, though, that most of the work in these sectors is done on a project basis. That makes it harder for our graduates to find a steady job. They typically work at one project for half a year or a year and then move on.”

Master’s programme: Science Education and Communication URL: • www.uu.nl/programmes/sec for international students • www.uu.nl/masters/sec for Dutch students Contact: Dr Elwin Savelsbergh +31 (30) 253 8214 e.r.savelsbergh@uu.nl

[09-2010] Utrecht University it’s only Natural 11


Master’s programme: NanoMaterials: Chemistry and Physics Subject: Thesis research

Unexpectedly e in sustainability Name: Robin Jastrzebski Age: 23 BSc: Chemistry At: Utrecht University

Robin Jastrzebski is trying to optimize the processing of the plant compound lignin to serve as a source for bio-based chemicals. A rather abstract puzzle with very concrete applications in sight: sustainable materials.

Nearly all synthetic materials, whether it’s a plastic, paint, detergent, glue or drug, are ultimately derived from hydrocarbons. In our modern society this enormous variety of materials has become sheer irreplaceable. Or not? The chemical industry depends on the hydrocarbons produced during the refinery of crude oil. As long as a large and cheap supply of oil is available, the industry has nothing to worry about. But crude oil is slowly running out, and many energy companies are considering alternatives like bio-fuels and wind power. How can we still produce enough chemicals to satisfy our society?

Lignin as feedstock “By switching to biomass” says Robin Jastrzebski. To attain his Master’s degree in Nanomaterials: Chemistry and Physics he is currently doing a research project on lignin as a feedstock for the chemical industry. Lignin is the substance that gives

e “The challeng the is to remove ut oxygen witho disrupting the aromatic rings of carbon and hydrogen" 12 it’s only Natural Utrecht University [09-2010]

rigidity to plants: it makes them ‘woody’. Plants contain 15 up to 25 percent of this compound. It is currently produced as a by-product of paper, so large quantities are already available. Presently, the lignin is burned to power the paper mills, but it is a rather poor fuel. Transformation of lignin into more valuable chemicals would therefore be ideal. Investigating alternative sources of fuel and plastics used to be a very popular occupation during the seventies and eighties, but got out of fashion after the crude oil price dropped again. A couple of years ago, scientists picked up the materials and research plans they had abandoned. Sustainability is now ‘hot’, as well as is nanotechnology. Both are combined in the research group Inorganic Chemistry and Catalysis that Robin took seat in. “Lignin is a very complicated polymer”, Robin explains, “and it consists of several different monomers. The composition also varies depending on the plant the lignin comes from.” To overcome this complexity Robin experiments with smaller, simpler model compounds.

De-oxygenation As a starting point for further chemical transformation, the hydrocarbon molecule requires an as low amount of oxygen groups as possible. Robin’s job is to get

rid of this oxygen. “The challenge is to remove the oxygen without disrupting the aromatic rings of carbon and hydrogen the lignin molecule possesses. These rings are valuable; they form the core of many chemicals and pharmaceuticals.” A trick to achieve this goal can be cribbed from oil refineries. Molecules to be found in crude oil contain sulphur instead of oxygen. After distillation an important step takes place: the desulphurization of the molecules. The same catalyst facilitating this process might be useful for the de-oxygenation of lignin. However, Robin emphasizes, it has to be optimized. “The catalyst is currently adapted to desulphurization, so it is reasonable that de-oxygenation is suboptimal.” A catalyst is a substance that facilitates a reaction process, but does not change itself. In this case it first attracts and binds the sulphur or oxygen atoms and subsequently releases them. Robin puzzles with the circumstances for his catalytic process, trying to improve it and resolving what exactly happens during the reaction. The catalyst consists of tiny metal particles, supported on a porous material, such as silica or alumina. In an ideal world, the reaction only takes place on well-defined sites on the metal particle. In reality, many different kinds of particles may be


ending up y

present and the support material changes the reactivity as well.

Side reactions It is very important to analyze the side reactions that are occurring. At the same time, this part is the toughest, Robin says. “For some of these reactions it is very difficult to figure out what by-products you obtained, since we’re talking about very small amounts. But these by-products are crucial, because they contain a lot of information about what is actually happening in the reaction container. Once we know what is going on, we may adjust the catalyst to do better de-oxygenation.” Robin shows his lab materials. The reaction takes place in autoclaves, containers with a wall of at least

a centimetre of solid steel, able to sustain very high pressures. Several tubes and valves are connected to it, to add gas to the reactor and regulate temperature and pressure. After the reaction of the model compounds and catalyst has finished, which may take several hours, an analysis using mass spectrometry or gas chromatography follows. The peaks these machines produce are like a cryptogram Robin has to solve.

Noble quest Robin will not work with lignin at all during his research project. No big deal, he finds. “I am working on a very small part of the project, but my colleagues will use my results to continue the quest. Without my work on these simple molecules my colleagues would certainly lose their

"Without m y work on these simp le molecule s my colleagues would cert ainly lose their g rip on the complex lig nin itself.”

grip on the complex lignin itself.” It is a plausible assumption that this ambitious and noble quest will lead to practical applications, since the project is part of a larger initiative called CatchBio, a cooperation between Dutch universities and a large consortium of chemical and catalyst producing companies. “These companies will apply for patents. That might slow the scientific process at certain stages, but we’ll be able to make use of their experience as well.” That is what made this research field fascinating for Robin: “I did not aim to end up in the sustainability field beforehand, but I wanted my project to be useful. Now that I got into this world, it is grasping me even more.” 

Master’s programme: Nanomaterials: Chemistry and Physics URL: • www.uu.nl/programmes/nano for international students • www.uu.nl/masters/nano for Dutch students Contact: Annik van Keer a.a.j.vankeer@uu.nl +31 30 253 4939

[09-2010] Utrecht University it’s only Natural 13


Graduate School news

Utrecht Natural Sciences and Mathematics 38th in Shanghai ranking The Natural Sciences and Mathematics of Utrecht University are on the 38th place in the prestigious ‘Academic Ranking of World Universities’ of this years Shanghai ranking. Utrecht University is ranked highest of all universities in the Netherlands, on the 50th place.

Raymond Snellings appointed professor

Master the Universe! The University Museum in Utrecht offers an exhibition on the search for “a theory of everything”. Under the title Master the Universe!, Nobel Laureate and Professor of theoretical physics Gerard ’t Hooft shows the visitor the solutions and challenges in the research. Several topics in the field of physics are presented for a broad audience, and information on the life of professor ‘t Hooft is on display.   More information: www.mastertheuniverse.nl

The Executive Board appointed Dr Raimond Snellings as Professor of Heavy Ion Physics with specific research and teaching commitments for a five-year period. The appointment will reinforce the collaboration between the Subatomic Physics group (Physics and Astronomy) and the National Institute for Subatomic Physics (Nikhef).

Δ ITP Theoretical Physicists in the Netherlands joined forces to offer the best of their education to all physics students in the delta Utrecht, Leiden and Amsterdam. Starting in September 2010, a new course for advanced Master’s students and PhD students will be offered jointly. The information is available here: http://staff.science.uva.nl/~jcaux/DITP.html

Debye Institute conducts award-winning nanotechnology research An international team of researchers under supervision of the Debye Institute has demonstrated that complex nanoparticles can be studied in unprecedented detail. The results are available online following their publication on 6 June in an article in Nature Nanotechnology. Several days later, Matti van Schoonenveld received a Young Scientist Award for this research.

Subsidies A selection of subsidies awarded to research proposals in Natural Science is listed below: • Vici subsidies have been awarded to Gleb Arutyunov and Stefan Vandoren of the Institute for Theoretical Physics. A maximum of 1,500,000 euro per person enables the researchers to develop their own research group over a five-year period. • The Freudenthal Institute has received an EU subsidy of 390,000 euro to broaden the scope of access to didactic knowledge in the field of mathematics and science. • Professor Moerdijk and Dr Van Oosten (Mathematics) and Professor Swierstra and Dr Dastani (Information and Computing Sciences) will all receive a 200,000 euro subsidy for a four-year period. PhD researchers will be appointed as soon as possible. • The European Research Council has awarded an ERC Advanced Grant of almost 2 million euro to physicist, Professor Emeritus, Bernard de Wit.

14 it’s only Natural Utrecht University [09-2010]


Master’s programme: Astrophysics & Space Research Subject: Challenges of a Master’s programme

Motivation for pro active participation Fuelled by his sister’s tales of her Utrecht

experiences, João Ferreira attended the Utrecht University Summer School in Astrophysics. The Lisbon University graduate had a gut feeling that the Dutch academic culture was just what he was looking for. In September next year he expects to finish his Master’s thesis for Astrophysics & Space Research.

Name: João Ferreira Age: 22 BSc: Physics At: Lisbon University, Portugal Looking for change “After my Bachelor’s degree, I wanted a change of environment”, explains João. “So I looked for a challenging programme taught in English, somewhere in Europe. Utrecht ticked all the boxes and my sister was already here for her PhD. She was very enthusiastic, so I was off to Utrecht.” Raising funds is a major barrier for students to go abroad, João feels. “Securing a scholarship was my top priority. After that, the application was easy enough.”

Culture shock João describes his first classes in Utrecht as a ‘shock’. “The mentality here is completely different. It’s very hands-on. For instance, practical classes with computer simulations are a lot more recurrent.” Luckily for João he did find the change he was looking for in the Utrecht academic culture. “The interaction between staff and students is more equal than in Portugal. As a student I get the feeling my ideas and opinions are appreciated, which in turn motivates me to participate pro actively in class. Starting the Astrophysics programme, the knowledge gap was only the astrophysical mindset, which is different from that of a phisicist in some points, more practical and the overall use of the standard astrophysics/publishing tools like LaTeX and IDL or SPEX.”

sses for la c e g a u g n la “Dutch an excellent example offer t to know e g o t y it n u t r oppo people.” Feeling at home Apart from the academic atmosphere, João needed some time to get accustomed to his classes. João recalls that he was the only international student in a small group, and didn’t immediately feel at home. “That changed over time. Maybe my experiences in the Summer School made it easier for to integrate. But mostly it’s important to go out and talk to other students. Dutch language classes for example offer an excellent opportunity to get to know people.”

Deserved reputation All in all, João is very content with his choice. “The Utrecht Physics has a good reputation, which is completely deserved. The curriculum is flexible and up-to-date, and I love the attention to students’ input and creativity. I’m also pleasantly surprised by the specificity of some of the subjects; you get the chance to dig deep. ” 

Master’s programme: Astrophysics & Space Research Url: • www.uu.nl/programmes/astro for international students • www.uu.nl/masters/astro for Dutch students Contact: Dr Frank Verbunt +31 (30) 253 5207 f.w.m.verbunt@uu.nl

[09-2010] Utrecht University it’s only Natural 15


Master’s programme: Energy Science Subject: Study abroad

Geert-Jan Persoon was one of the first university students to test the new exchange agreement between Utrecht University, Hogeschool Utrecht, RWTH Aachen and the South African Tshwane University of Technology (TUT) in Pretoria. Doing research at the solar water heating programme within energy company Eskom, he found a workplace full of helpful people, and a country still trying to shake off its history of apartheid.

New programme

Name: Geert-Jan Persoon Age: 26 BSc: Earth Sciences At: Utrecht University

16 it’s only Natural Utrecht University [09-2010]

Geert-Jan’s trip to South Africa was somewhat of a test run, as the exchange programme had just been established. That’s why the order in which he organised his exchange was a bit different as well. “Usually you decide what you’d like to research and then try to find a suitable location. In this case I indicated my interest for Africa and my coordinator asked me if I would like to go to South Africa in this new programme.”

Linking science and business This proved not to be the ideal working method. Geert-Jan: “Because we formulated the research question


STUD

ABR

Y

OAD

Testing the water in Pretoria in Utrecht, it was harder for the staff in Pretoria to help me get started. As a consequence the three month period was a bit short to finish research.” The research itself, however, was right up Geert-Jan’s alley. “Energy Science is all about linking science and business in a meaningful way. I researched the implementation of a high profile solar water heating programme by Eskom, the state energy company in South Africa, trying to find out how to improve its results.”

Inviting and helpful Despite the difficulties starting up, Geert-Jan enjoyed his stay in Pretoria. “Being a guinea pig made my stay even more interesting. The TUT staff was very inviting and helpful, and it was interesting to experience a different way of working. Interaction in South Africa is less formal and less strict. That also means that your e‑mail messages aren’t always answered as expected, and appointments don’t always take place at the agreed time. Once you get the hang of it, it’s a quite relaxing way of doing business.”

Racial awareness Social life was unlike anything Geert-Jan had ever experienced. “South Africans in Pretoria are still very much aware of race. Unfortunately there was hardly any interaction between us exchange students and the mostly black TUT students, because we didn’t follow any courses

“Being a guinea pig made my stay even more interesting.”

“Energy Sc ience is al l about link ing scienc e and business i n a meanin gful way. ” and did our research mostly in our own office. Although the period was already short, in hindsight it would have been nice to follow some classes together with TUT students. Fortunately we got to meet lots of friendly people - both black and white - outside the campus.” Another dominant issue is safety. Geert-Jan: “When you cross Pretoria, you go from fence to guarded fence, and from barrier to code locked door. It made me realise how freely we can move in the Netherlands.”

Good results None of Geert-Jan’s objections made him change his mind about his time in Pretoria, however. “I spent time with kind people, in a beautiful country and did interesting research. And on top of that Eskom came to some of the same conclusions I did, and changed its approach to the solar water heating programme accordingly.” Not bad for a first time exchange. 

Master’s programme: Energy Science URL: • www.uu.nl/programmes/ensci for international students • www.uu.nl/masters/ensci for Dutch students Contact: Dr Wilfried van Sark +31 (30) 253 76 01 w.g.j.h.m.vansark@uu.nl [09-2010] Utrecht University it’s only Natural 17


Master’s programme: Mathematical Sciences Subject: Design your own Master’s programme

Name: Sebastian Klein Age: 26 Education: Mathematics At: Freiburg University, Germany

A national maths curriculum with international attraction

Sebastian Klein, student “The choice for Mathematical Sciences came kind of natural to me. I always knew I wanted to do fundamental research, simply because there is something inherently beautiful about the sheer logic of theoretical structures. The idea of absolute truth appeals to me. The programme at Utrecht University allows me to pursue my interests in a wide variety of courses.”

Lots of opportunities “I studied Mathematics for two and a half years in Freiburg, before coming to Utrecht via an exchange programme. I used my time in Utrecht to orient on staying here and doing my Master’s programme. Two things struck me. One is the wide variety of courses to choose from, thanks to Mastermath. Dutch universities join forces in this programme to offer a number of high quality courses. Another is the relative freedom to pursue one’s own interests. I basically just picked the subjects I liked best.”

Taking initiative “For exchange students it might be a bit harder to gather information on the different available courses, because you’re not familiar with the organisation yet. It’s all the more important to take the initiative in contacting other students and asking them about their experiences. When I was writing my Master’s thesis, my Master Tutor professor Cornelissen was of great help in focussing my research. His knowledge and experience on the intersection of physics and mathematics really helped me along.”

"The prog ramme at Utrecht University allows me to pursue my interests in a wide variet y of cour ses.”

Courses Sebastian took: Algebraic geometry (*) Algebraic number theory (*) Cryptology (*) Elliptic curves (*) Homological algebra Invariant theory with applications (*) Partial differential equations (*) Topics in Galois theory (*) Topology of smooth manifolds Toric geometry (*) (*) = Mastermath

18 it’s only Natural Utrecht University [09-2010]


The Master’s programme Mathematical Sciences offers students a wide variety of courses. A large part of the curriculum is organised nationally in the programme Mastermath. Students looking for a versatile, high quality mathematics research programme with a broad scope might want to take a closer look.

Name: Prof. Gunther Cornelissen Age: 39 Education: Licentiate and PhD in Mathematics At: Ghent University, Belgium

Prof. dr. Gunther Cornelissen, Master Tutor “Every student that enrols in Mathematical Sciences is assigned a Master Tutor. The expertise of the Master Tutor always reflects the students’ interests. The first thing the Master Tutor does, is matching the student’s interests with the available courses. That’s not a lengthy affair; we’re usually done within an hour. During the rest of the Master’s programme the Master Tutor is the student’s guide, exchanging e-mails when necessary.

Prearranged paths The Master’s programme Mathematical Sciences offers a good deal of courses. Part of the curriculum is national, clustered in the programme Mastermath. Subjects in Mastermath are arranged along thematic lines, so there are some prearranged paths to follow. Within the confines of those paths, students can choose their own subjects. As a Master Tutor I do however advise them on courses that might fill a gap in their knowledge.

Shaping each other’s research While they are writing their Master’s thesis, students are in weekly contact with their Thesis Advisor. They might ask me: ‘I’ve read this, could you elaborate on that’, or: ‘I have been pondering this formula and I think I’ve got it, am I correct?’ I answer their questions to the best of my knowledge. In a way, I take part in the research of all my students. Apart from that, students talk a lot about their research amongst each other. That way they partly shape each other’s research.

International compatibility Sebastian had little trouble adapting to the programme here in Utrecht. Of course that is due to his intelligence and hard work, but it also means that the Master’s programme Mathematical Sciences is quite compatible with the curriculum at other universities. Bear in mind that Freiburg, where Sebastian studied, hadn’t even implemented the Bachelor-Master structure at the time of Sebastian’s exchange. The flexibility of the Master’s programme Mathematical Sciences and the opportunities to complement and extend one’s knowledge are two of its biggest strengths.” 

and y it il ib x e fl "The ities to n u t r o p p o the xtend e d n a t n e m comple e are two g d e l w o n k one’s gths.” n e r t s t s e g of the big Master’s programme: Mathematical Sciences URL: • www.uu.nl/programmes/mathsci for international students • www.uu.nl/masters/mathsci for Dutch students Contact: Dr Yuri Kouznetsov Dr Thijs Ruijgrok +31 (30) 253 1528 +31 30 253 1525 i.a.kouznetsov@uu.nl m.ruijgrok@uu.nl

[09-2010] Utrecht University it’s only Natural 19


Master’s programme: Science and Business Management Subject: Challenges of a Master’s programme

Ruud Schravesande is very pleased with his choice for the Master’s programme Science and Business Management. His biggest challenge: trying to find out what he likes best, in time to decide on a subject for his final internship.

Name: Ruud Schravesande Age: 27 BSc: Biology At: Utrecht University

Springboard to a career in business Being a researcher has its advantages, says Ruud: “I love the freedom of doing research: getting up in the morning, not knowing exactly how this day will end up, going to the lab and writing a final report. But I don’t see myself doing the same for another four years, as I miss the interdisciplinary cooperation of a company setting. That’s why I chose Science and Business Management, a programme that prepares me for a business career. I think the challenges of a commercial environment suit my tastes better.”

Eased into the programme Going from a Biology Bachelor to this particular Master’s programme didn’t pose any great problems for Ruud. “You kind of get eased into the programme. It’s very practical: doing lots of research. At the same time you take courses in which the focus of your presentations gradually switches to more marketing oriented. After that, you take more economics courses and then you start working on an external thesis. I’m really looking forward to taking the final courses and getting to know the field of work better.”

"Many businesses are eager to employ science graduates with analytical skills and commercial insight.”

20 it’s only Natural Utrecht University [09-2010]

Hard to make the most of internship This smooth transition does have a downside, Ruud feels, because it means the real introduction to the world of business comes late in the programme. Ruud: “The economics courses should give me a better idea of the various possibilities that are open to me after graduation. But I have to make the necessary arrangements for my internship before I take those courses. That makes it harder to decide what kind of internship fits my ambitions best. A missed opportunity, since an internship can be a good springboard for your career.”

Interesting possibilities That minor setback is not going to put Ruud down, however: “I took an honours course in entrepreneurship to see if I made the right choice. It gave me better insight in career possibilities, and also brought me in contact with people from companies that may offer interesting possibilities for my external thesis. That’s the upside: many businesses are eager to employ science graduates with analytical skills and commercial insight.” 

Master’s programme: Science and Business Management URL: • www.uu.nl/programmes/sbm for international students • www.uu.nl/masters/sbm for Dutch students Contact: Anje de Graaf +31 (30) 253 9333 h.a.degraaf@uu.nl


Master’s programme: Particle Physics Subject: Working in research

CERN: where worlds collide Utrecht University has just appointed Raimond Snellings Professor of Heavy Ion Physics. As he already works at Nikhef and as a visitor at CERN, Raimond pretty much has a researcher’s dream job. It takes hard work, but Raimond believes

Name: Raimond Snellings Age: 42 Education: doctoral in Physics and PhD study At: Utrecht University

at CERN today’s students have every opportunity to take part in a revolution in physics. Ideal world “Most students look up to CERN and the Large Hadron Collider in Geneva, and who can blame them?” Raimond asks. “For a scientist like me it’s the closest thing to an ideal world. I get to work with a thousand top scientists from thirty countries, in a trend-setting group. Together we work towards a single goal: finding out how particles behaved one millionth of a second after the Big Bang. We’re almost literally going back to the beginning of the universe.”

Ample opportunities Its status as the top institute in particle physics shouldn’t deter ambitious students, explains Raimond. “Right now CERN needs a lot of people to labour on the experiments, which are really just starting. So there are ample opportunities for people to do their PhD research in CERN-Geneva. It takes a curious mind, and a willingness to work hard. You work with cooperative people with a

Master’s programme: Particle Physics URL: • www.uu.nl/programmes/paph for international students • www.uu.nl/masters/paph for Dutch students Contact: Prof Thomas Peitzmann +31 (30) 253 2512 t.peitzmann@uu.nl

shared interest, but there’s also a competitive element. You have to be able to take the heat.”

Undiscovered territory CERN may be a demanding environment, the rewards of working there are well worth it, Raimond believes. “The institute is obviously well equipped, so working conditions are really good. But more important: we’re venturing into truly undiscovered territory. Everyone expects the outcome of the experiments at CERN to radically change our views of physics. Theory predicts that wholly new things are going to happen in that big tunnel.”

More options Although Raimond is passionate about his scientific work, he stresses there are many other options for his students. “Some people I took classes with at university switched towards a business career, even after executing PhD research or after a post doc position for several years. It’s funny to see the parallels between their work and mine. An investment banker may have a totally different mission and different goals, but we both analyse and arrange data on a daily bases, do mathematical work and apply risk management. Having said this I still insist to take a group of students to CERN every year. They usually return very, very enthusiastic.” As always, the proof of the pudding is in the eating. 

[09-2010] Utrecht University it’s only Natural 21


Master’s programme: Theoretical Physics Subject: Different degrees, same Master’s programme

Fundamen choosing Physics Name: Selma Koghee Age: 22 BSc: University College – major Science At: Utrecht University

Selma Koghee attended University College Utrecht before deciding to immerse herself in the very basics of nature. As it turned out, after a period of hesitation, Selma will continue the Master’s programme Theoretical Physics.

1

Why did you choose this Master’s programme? “To be honest, I didn’t know what I wanted to do exactly. I wanted to gain a basic knowledge of how nature works and this seemed like an ideal starting point. Besides, the programme is highly ranked, and I was looking for a challenge.”

2

How did you prepare for the programme? “I attended University College and that leaves a good many options open. I did choose courses to prepare myself for Theoretical Physics though. When I went on an exchange, I deliberately took physics courses, with this Master’s programme in mind.”

3

Were you up to the task when you started the programme? “I wouldn’t say I wasn’t up to it, and I did pass my exams, but I do notice a difference between me and the other students in their approach to the subject matter. Students

"The programme is focu sed on describing things at the most fundamental level, which leaves you with a mere calculation. " 22 it’s only Natural Utrecht University [09-2010]

who did their Physics Bachelor here, knew better what was expected of them. At University College students are expected to pass every course at once, whereas here it is possible that a large percentage of the students fail a course. This programme focuses on acquiring knowledge through exercises. At some foreign universities the focus can be more on learning established facts.”

4

What was the most challenging part of your first year? “Even though it might sound a bit naïve, I wasn’t prepared for just how abstract the subject matter is. The programme is focused on describing things at the most fundamental level, which leaves you with a mere calculation. For me, the relevance to what’s going on in the real world was too hard to see at times.”

5

How did you get by? “I considered switching to another program, until the study advisor suggested a research topic very closely related to experiments about a material with exciting properties and also possible practical applications.”

6

What was the most fun in the first year? “I liked a project with other students. We presented an experiment in which electrons moved without applying net force. It makes you realise that you are in fact dealing with very real natural phenomena.”

7

What suggestions do you have for other students contemplating this programme? “You have to have affinity with mathematics and know that it can be abstract at times. However, I learned that the field of theoretical physics is much more varied than I thought when I started, so don’t be afraid to talk to people about the possibilities you have for your thesis and after the master.”


ntals for Theoretical Selma Koghee and Rakpong Kittinaradorn come from vastly different backgrounds. Both ended up in the Master’s programme Theoretical Physics at

Name: Rakpong Kittinaradorn Age: 23 BSc: Physics At: Mahidol University, Thailand

Utrecht University. They explain why, and talk about their experiences one year after their enrolment.

Rakpong Kittinaradorn got his Bachelor’s degree in Physics in Thailand and then he moved to Utrecht. Here, he tested the waters in the Summer School in Science, before admission for the Master’s programme Theoretical Physics .

1

Why did you choose this Master’s programme? “Thailand is not exactly a scientific hotspot. Most talented students I know went abroad after graduation. Since language can be quite a barrier, lots of them choose England or the United States. All Utrecht programmes in Science are also taught in English, and some of my friends who had been here before were very enthusiastic. So I decided to join the Summer School to find out if it suited me. It did.”

2

How did you prepare for the programme? “I didn’t choose specific courses in Thailand to get prepared. But after the Summer School I realised that I would have a knowledge arrears. In order to fix that gap, I educated myself by reading and studying when I got back home.”

3

Were you up to the task when you started the programme? “My knowledge and skills were sufficient, but language turned out to be problematic, even though I had taken English classes before leaving for Utrecht. I dealt with that by studying a little bit harder and asking my fellow students for clarification. I’m ok now.”

ool I "After the Summer Sch ve a realised that I would ha knowledge arrears."

4

What was the most challenging part of your first year? “Apart from the language, there were no big cultural issues. Maybe I didn’t expect the programme to be as serious as it is, since I had only experienced the Summer School. It’s hard work.”

5

How did you get by? “Well, I kept my eye on the prize! Lectures and exercises are extremely well organised and of high quality, so after your hard work there’s a big reward.”

6

What was the most fun in the first year? “It’s hard to tell. I think it’s the variety of subjects you encounter. I’m still trying to make up my mind about a thesis subject. There’s just so much to choose from. I’m checking the website and talking to other students to try and create a shortlist, but so far to no avail.”

7

What suggestions do you have for other students contemplating this programme? “Be serious about it. I would have been in trouble if I hadn’t self-educated beforehand. The academic level can be quite a bit higher than that of a foreign Bachelor.” 

Master’s programme: Theoretical Physics URL: • www.uu.nl/programmes/theph for international students • www.uu.nl/masters/theph for Dutch students Contact: Prof. Cristiane de Morais Smith +31 (30) 253 3062 c.demoraissmith@uu.nl [09-2010] Utrecht University it’s only Natural 23


Master’s programme: Stochastics and Financial Mathematics Subject: Thesis research

Comparison of stochastic models Statistics and probability are usually about dependencies. Lotte van den Berg made stochastic comparisons of Markov queuing networks through coupling. This can be used to analyze processes at call centres and complex phenomena like the spread of diseases.

A while ago Lotte van den Berg asked her Master’s thesis supervisor Lasse Leskelä a remarkable question: “How many colleagues do you think really comprehend the article you published two years ago?” Leskelä, research fellow at the Department of Mathematics and Systems Analysis of Aalto University in Finland, looked at the sky thoughtfully and started enumerating the names. “That makes four, and with you, five.” The article Lotte and her supervisor talked about was the starting point of her Master’s thesis in Stochastics and Financial Mathematics. As this anecdote illustrates, the research field Lotte got involved in is quite young and pioneering. This field is all about comparing stochastic processes by making use of coupling. This is a subfield within the larger field of ‘Markov queuing theory’, named after the famous Russian mathematician Andrej Markov, who lived in the late nineteenth and early twentieth century. The specific field Lotte worked in during her thesis project was so new that there was not even an introductory book she could read to prepare herself for the real stuff.

Communication networks So far it all sounds very complicated and daunting, but surprisingly Markov queuing is applied in very regular daily life situations, Lotte tells. “At a call centre or in a supermarket, customers arrive in a random manner and wait in line to be served. How

ork "The topic of my w f the is the comparison o o queuing distributions of tw ing." networks with coupl 24 it’s only Natural Utrecht University [09-2010]

long they will have to wait, depends on several stochastic variables: the handling speed of the call centre employee, the difficulty of the question, the amount of questions. In a supermarket customers can even switch lines while they are waiting. After service, the customer leaves or switches to another service station. Call centres are the easiest examples of applications of such queuing networks, but you can think of any model where queues play a role.” Lotte was interested in system quantities, such as the number of customers in the system, the waiting time or the busy period of a service station. “Usually, when analyzing complex queuing models, the means of system quantities are studied. But in my thesis, my specific aim was to compare the distributions of the parameters we are interested in.” Information about the distribution of the number of customers in the model is worth more than just a mean, because this fully describes the behaviour of the process. To be more precise, the topic of my work is the comparison of the distributions of two queuing networks with coupling. To compare two processes, these two must somehow be comparable. This is difficult, for example, when the processes take values in different state spaces. Coupling is a trick to define a new, third process which behaves somehow like the two original processes that we want to compare. The downside of these realistic and complicated models is that they are difficult to analyze. Therefore, bounds are introduced. What Lotte did was compare the complicated with a simplified model of the same process.

Pencil and paper work Lotte has a mind-bedding job. Nevertheless, while modelling she did not use any computerized help. “I searched for information on the web, but did all the real work with a pencil and a paper. Writing down equations,


Name: Lotte van den Berg Age: 25 BSc: Mathematics At: Utrecht University drawing arrows showing relations and playing with variable dependencies, that was my challenge. And her research was worthwhile. A related research group worked on a similar comparison problem as Lotte did. “They finally got some results, but those were very ugly and difficult to use. So I put aside their calculations, used my formulas and showed it did not need to be so complicated.” “Mathematics is in a way a matter of writing down your formulas very clear and carefully” Lotte tells with some diffidence. “Even though only a very small group of people are able to understand the theory, and my formulas do look impressive, this kind of mathematics is in fact rather simple; the models can all be explained in an intuitive way using plain language.” If that is the case, then how is it possible that she did not understand the subject she was working on for months? “That is a common phenomenon. The topics we work on in mathematics are so conceptual and – in this case – theoretical, that it takes time to really get into a subject. I probably have read the article of Lasse Leskelä thirty times now.”

"I put aside their calcul ations, used my formulas and sh owed it did not need to be so complicated.” Hidden world The Markov queuing theory can be applied to many more processes. The distribution of data packages on the internet for instance, or the spread of infectious diseases. Lotte concludes: “It are those applications that made the subject exciting for me. I expect the field will grow in the next decade. Processes will become more complex, and higher standards will be set for models. But for most people the models will remain a hidden world.” 

Master’s programme: Stochastics and Financial Mathematics URL: • www.uu.nl/programmes/sfm for international students • www.uu.nl/masters/sfm for Dutch students Contact: Dr Karma Dajani k.dajani1@uu.nl +31 30 253 1424

[02-2010] Utrecht University it’s only Natural 25


Subject: Summerschools in Science

Summerschools Mihaela Verman was invited to attend the Summerschool Name: Mihaela Verman Age: 22 BSc: Computer Science At: University of Bucharest, Romania

in Applied Functional Programming, after being admitted to the Technical Artifical Intelligence programme. That’s how she first found out about the Summerschools offered by Utrecht University.

How was your housing arranged? ‘The housing for the Summerschool was arranged by the SSH. The real problem was my accommodation after these weeks, since I missed the optimal period of applying through the SSH. I eventually got lucky and found accommodation in Zeist, a town close to Utrecht, but I think that housing international students is a very big problem for the University. My advice: start looking for housing in time!’  

What was the hardest part of the Summerschool?

How were the contacts with your fellow students and lecturers? ‘I think that the amazing communication between students and lecturers kept us going, even though the courses were sometimes hard. In our free time we had the opportunity to socialize, attend different activities together. This made us more open to interesting personal and useful substantic conversations. I learnt a lot from both the lecturers and the fellow students.’  

Now you’re in the Technical Artificial Intelligence programme. Does it match your expectations?

‘Probably that was to get accustomed to the different way of programming. And maybe the schedule, because some times it felt a little bit too tight. But it was really worth it: we had some very nice results in the end. The fact that the course wasn’t that easy contributed to the sense of accomplishment that we eventually achieved.’

‘Yes, pretty much. But I’m still learning new surprising things about what a Master’s programme can be like, so I guess that now I could say that it exceeds my expectations.’  

Which educational part(s) of the two weeks is Summerschool do you like best?

‘Yes, I do think that the Summerschool gave us good insight into the education in the Master’s programmes. I enjoy the clear way of presenting the subjects and the concept of learning by doing real applications. The Summerschool was intense, but the Master’s courses are also. We do have to concentrate on fewer courses on a more limited time interval. I think that the structure of the academic year is a very good thing. ‘

‘I liked both the lectures and the lab sessions. I also liked the fact that there were two different tracks: beginner and advanced. The best part though was actually the final project. That gave me a good sense of accomplishment.’

course wasn't "The fact that the d to the that easy contribute ment that we h is pl m o c ac f o e s sen eventually achieved."

26 it’s only Natural Utrecht University [09-2010]

Do you think Summerschools in Science are representative for the education in the Master’s programmes?

Looking at our education as well as culture, can you mention some differences in comparison to your home? ‘In Romania there is much more focus on theoretical aspects. Because in Bachelor’s studies the group sizes at the lectures are quite big the interactivity between lectures and students is less.


in Science

How did you get acquainted with the city of Utrecht and the Netherlands?

‘Sometimes I just go exploring on my own, but I prefer going in small groups. We first used maps very often, by now we just go off and see what comes up. I like cycling quite a lot and go on cycling trips in the near-by cities and towns. I think the museums in the Netherlands are very interesting, so each time I visit a city I also target one of the museums I haven’t seen before.’

"I do think tha t the Summerschool gave us good insight into the education in th e Master's progra mmes. "  

Which place in Utrecht do you like best? ‘Most of all I like the parks and I regret that the on campus Botanical Garden isn’t bigger, because I enjoy spending time there.’ 

More information: www.uu.nl/science/summerschools for international students www.uu.nl/beta/summerschools for Dutch students

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Drukkerij Zuidam Uithof

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In Utrecht I experience the enthusiasm helps the process of learning. At the beginning of a course I already know why certain subjects are important and therefore have to be studied. It is also helpful that the theory is supported with tangible examples. Another difference I have noticed is that students and teachers communicate much better, maybe because the students are used to do so from high school.’  

[09-2010] Utrecht University it’s only Natural 27 [02-2010]


Master’s programmes at the Utrecht Graduate School of Natural Sciences

Entrance Requirements of our Master’s programmes *

Biology Information Technologies in Science and Society Business Informatics m Computing Science m Game and Media Technology m Technical Artificial Intelligence m Foundations of Natural Science Astrophysics & Space Research ± Mathematical Sciences ± Meteorology, Physical ± Oceanography and Climate Nanomaterials: Chemistry and ± Physics Particle Physics ± Theoretical Physics ± Scientific Computing ± Stochastics and Financial ± Mathematics History and Philosophy of Science History and Philosophy of Science m Science & Society Energy Science ± Science Education and x Communication Science and Business Management x

Academic BSc Degree (Utrecht University) Computer Information Chemistry Mathematics Science Science m m m m

m x x x

± ±

x m m m

Physics

Other BSc degrees (with restrictions)

m m m m

m m m m

HBO-i Artificial Intelligence, HBO-I Artificial Intelligence, HBO-I Artificial Intelligence, HBO-I

± ±

± x

x x

±

±

±

x

Geographical Sciences

x

±

±

x

HLO

± ± ±

± ± ±

± ± x

x x x

±

±

x

x

m

m

m

m

x

x

±

±

±

x

Geographical Science, HBO

x

x

x

x

x

Life Sciences, HBO

x

x

x

x

x

Life Sciences, HBO

x = admittance with no restrictions m = specific minor needed for admittance ± = specific knowledge/courses needed for admittance HBO = higher professional education * This is a global outline of the entrance requirements for the mentioned Master’s programmes, of which no rights may be derived. For the exact requirements please check the website of the programme of your choice or contact the programme coordinator.


Master’s Magazine Universiteit Utrecht, It’s Only Natural