Geometry, Imaging and Computing

Geometry, Imaging and Computing

A short note to myself: There is the new journal “Geometry, Imaging and Computing” published by International Press which looks interesting for papers inbetween computer vision and computer graphics.

 

Open PhD position in applied analysis, mathematical imaging, inverse problems

I have an open position for a Scientific Assistant/PhD student available. The salary is according to TV-L EG 13. (Don’t know what that means? Have a look here.). The position starts at 01.09.2013 (earlier start is possible) and is initially limited to two years; further extension is possible and for a PhD student, at least three years are planned.

Candidates should

• have a degree (Masters or Diploma) in mathematics above average,
• have very good knowledge in numerical mathematics and functional analysis,
• have good knowledge in scientific computing or optimization,
• know German well and
• have strong interest in applied mathematics. Also, bring a high commitment for scientific research.

The responsibilities include

• participation in teaching and
• independent but supervised research in field of applied mathematics (especially mathematical imaging and inverse problems).

Please send applications including CV, copies of certificates and letters of recommendation (if any) in electronic form directly to me. Deadline is the 30.06.2013.

If you would like to post the job advertisement at you bulletin board, here’s the pdf file.

 

A digital mathematical library for the whole world

Although I think that most readers of this blog also follow “What’s new” , I could not help to share the most recent post there also here. Yesterday, Terry Tao featured a guest post by nobody less than the present president of the International Mathematical Union (IMU), Ingrid Daubechies.

The post is “Planning for the World Digital Mathematical Library” and, in a nutshell, Ingrid Daubechies present the plans of the IMU to build a new online digital library for mathematics and asks the math community for input to make this library most useful using the best of the available technology. Go and read the post. Then start thinking about how you work with mathematical literature (How do you find it? How do you use it? Do you archive it for yourself? Do you rely on other online databases? How do you communicate about articles and books with others?). This quickly generates ideas for the mathematical library: Errata could be tracked automatically, one could have a way to archive notes for articles you read directly linked to the article/book, these notes could be public, semi-public or shared within some community, the library could be used to have reliable and unified identifiers for bibliographies (no more taking care or messy merging of bibtex-files),… So go ahead and provide your input – this can be big.

 

What happens when you get a “Ruf” (i.e. a job offer)

In a previous post I wrote about my experience with three job interviews for math professorships in Germany I had earlier this year. In this post I’ll tell the next part of the story. As the previous post on this topic, this post is a mixture of a description of my own experience and the general procedure. I won’t spoil any names of people or institution here but if you are interested in more details, feel free to contact me.

1. The “Ruf”

It turned out that I actually got two job offers which are called “Ruf” in Germany (which translates to “call”). The first one arrived (unofficially) by phone once the committee had formed its list. Some time later I received another phone call when the list had passed the Fakultätsrat. The official letter from the Rektor needed some additional weeks to arrive. The other offer arrived first by email (from the Rektorats office) and by paper mail a few days later. The first thing I did after each offer arrived, was to contact the speaker of my math department (by phone), to inform my colleagues (by email) and to inform the dean and the president (both by email and paper mail). I am not sure about the precise protocol here, but I thought it would be best to put the cards of the table.

Both offer-letters were short and formal and the most important thing was that they asked me to prepare a document in which I list my “Vorstellungen zur Ausgestaltung und Ausstattung” (unofficially this is called the “list of wishes”) which is the next point I am going to discuss:

2. The “List of Wishes”

I had no real clue how this document should look like. I was lucky that I could ask friends and that they were so kind to send me documents they had prepared for similar occasions. However, I do not think that there any rules here. University Rektors, Kanzlers or Presidents have negotiations with people from all kinds of disciplines and I am sure that the list of wishes from neuro-biologists, mechanical engineers or philosophers will differ considerably from the one I wrote.

I think the list of wishes should contain:

• A section about what you plan to do. I think this one is difficult because it should be concrete but honest and also be written in layman’s terms.
• A section about the workgroup which you have in mind. Especially important: How many associated positions for PhD students/teaching assistants do you expect the university to provide? Do you bring any third party funded people?
• A description of the office space you need.
• A list of what you wish for as “start-up funding” (buying computers, laptops, furniture, books, servers,…).
• Your wishes for a yearly budget (for traveling and guests).
• What salary do you expect? Are there special reasons for a bonus?
• Any other circumstances which you find important.

Moreover, you should propose a date (or several) for the negotiations.

I found this list of wishes particularly difficult because it depends largely on the structure and habits of the particular department/faculty and the university. Moreover, some things will be handled by the department and some things will be handled by the Rektorat and it is not always clear a-priori who is responsible for what. In any case it is helpful to speak to the dean of the faculty and any other people you know in the department to find out how this is organized. E.g. usually the organization of secretaries is basically fixed, as well as office space. It is in general a good idea (if not even necessary) to speak to the dean prior to the official negotiation because several things will be handled by the dean and not by the Rektor and if you did not agree with the dean about these things you can get in awkward situations in the negotiations. The salary is always discussed with the Rektor and the Kanzler (not with the Dean), there are a lot of rules according to which salary of professors is organized in Germany. There are federal laws, and university laws concerning the base salary and any additional bonuses. Moreover, these bonuses can be given permanently or temporary. If they are temporary then can be linked to a “target agreement” and this target agreement can or can not contain that the bonus will turn into permanent in case of success… I’ve heard that the base rule here is that it is better to overshoot than to undershoot.

Once you’ve sent your list of wishes you have to wait again. The Rektorat has to find a date for the negotiation and since several important people are involved (to be precise: Rektor, Kanzler and Dean), this may take some time. But after some time, I was contacted (by mail or phone) to agree on a date for the next important step: The negotiation.

3. The negotiation

In both case I was a little bit nervous when the day of negotiation came. As preparation I read several “Gesetzesblätter” again and moreover, tried to get information about the negotiation partners (especially the Rektor and the Kanzler because I knew the Deans already).

The actual negotiations took something between half an hour and one hour and besides Rektor, Kanzler, Dean and myself there was somebody from personnel administration. In both cases the conversation was basically conducted by the Rektor and started with some small talk.

In my first negotiation, the Rektor opened the official part by asking me to explain my research plans in layman’s terms. He seemed honestly interested and tried to suggest connections with other areas of expertise of the university. Next we moved into the list of wishes and then the Kanzler took over. We went over my list of wishes part by part and it was basically that the Kanzler said what the university could offer and what not. Sometimes the dean of the faculty was asked if the faculty could supply something but it seems that this was also prepared in advance. When it came to positions for research assistants, I was also asked about my plans to get third-party funding and how I would like to see and organize my work group. The last point was the negotiation of the salary. Here the dean left (somehow, salary is a highly confidential thing here) and the discussion was basically between the Kanzler and me. The Kanzler tried to briefly explain how the system for extra bonuses works and why he would only offer much less than I wished. I had a few things to reply and in the end, I did not feel that the negotiation ended with a definitive decision. However, they said that I should present my other offers when I get them and that they would be willing to think about outdoing them. Finally, we agreed on a decision deadline for me. The official offer arrived (first by email than in paper form) about a week later. I forwarded the official offer to the second university for the preparation of the next negotiations. I don’t know if this is the usual practice but again, I think that playing with cards on the table in easier here.

My second negotiation directly started with the discussion of the salary (there was no question about my field of research). The Rektorat had prepared a nice tableaux in which they illustrated my current situation, the other offer, and their offer side by side and basically they just topped the others by a small but non-negligible amount. Next we went over my list of wishes as in the first negotiation: The Kanzler said what they can offer and I could comment. Again, the last thing was to agree on a decision deadline for me. Also, the Rektor suggested that I could contact him I would “conditionally accept the offer” depending on smaller things (I am not totally sure what this could be, but salary can definitely be a point here).

In conclusion: I was a bit surprised that the negotiation was kind of a pleasant and open discussion but also that not too much negotiation actually happened (but this probably due to my limited “negotiation capabilities”…).

If I had to extract a general rule of thumb: Getting start-up funding for computers and furniture is easy (at least as a mathematician), increasing the yearly budget is harder, getting more positions for research assistants is hard if not impossible.

4. Next steps

After I had informed my faculty about the job offer, the administration asked, if they should prepare for “Bleibeverhandlungen” (negotiations to stay), i.e. if there was a chance that I would like to stay rather than leave and also if I truly consider to accept an offer (my honest response was that there was a chance for both, but I’ve heard that it could be a disadvantage to give a strong tendency at this stage). Some weeks later I received an official letter from the President of my university in which he invited me to negotiations to stay and asked me to present the official offers when I receive them along with another list of wishes…

Now the final steps will be: Preparation of the next list of wishes, negotiations to stay and finally, the most difficult part, forming a well-founded decision.

 

How amazing you’re already One, what a precious blog you’ve become

Happy Birthday regularize!

Exactly one year ago I started this math blog as a kind of experiment. Let’s see what has happened since then:

• I produced 46 posts (this one included) which I organized in
• 9 categories (well, most posts are in “math”…) and I used
• 55 different tags and there are
• 74 comments (out of which 22 are pings).

I blogged on papers I found and which I’d like to keep in some place (different from my filing cabinet or my harddisk), on topics which I’d got interested in, from conferences I attended, some posts were kind of off-topic and I started to post lecture notes.

Here are some curiosities extracted from the site-stats tool:

• The most used search term which brought a user here is “ivanov regularization” (63 times).
• On place two and three are “sarrus rule” (61 times) and “rule of sarrus” (44 times). I hope I helped to reduce the well know error which occurs in so many exams…
• The entry which got the most views (besides the homepage itself) is “Dual spaces of continuous function” (although I think it is not very good…).

Do I have some conclusion?

• Blogging needs time and effort. That’s how it is.
• However, blogging helps: It helps to read papers more thorough and to focus more on the questions “What does that mean for me?”, “How can I benefit from the new results?”. It also helps to get and keep in touch with other mathematicians. And it serves as some kind of archive for thoughts and ideas (although, I did not use this feature as much as I thought – probably because I remember things much better, once I blogged about them).
• Hence, I continue to blog the way I used to and look forward to year number 2 of regularize. If you have some suggestions I would like to hear them.

 

What they’ll ask in the job interview

It feels a bit awkward to write this post this very evening but, however, I planned to write it and so I’ll do…

I’ve been to some job interviews for lately (three to be precise). In all three interviews it happened that I was asked a question I did not prepare an answer for (although I had heard this question before and should have known that it’ll be asked). Hence, I thought it could be helpful to collect some standard questions here.

Probably I should add that I am talking about job interviews for professorships in mathematics in Germany. When I looked around on the web for tips and tricks for job interviews, I found a lot of tips for the US market. Most of the tips seem to apply to the German situation but I had the feeling that a post specifically for Germany could help.

When you apply for a professorship in Germany you send your documents as requested – usually that is:

• Your CV.
• Your list of publications.
• Your teaching record.
• A list of your projects (third party funded).
• A cover letter.
• A copy of your PhD certificate.

I have everything but the cover letter and the certificate within the CV. Sometimes you’ll be asked to send some kind of “teaching statement” or “research statement” and sometimes they ask for evaluation sheets of lectures. Recently I’ve seen more advertisements that directly say that they want digital applications via email.

Respect the deadline! Once the deadline has passed you have to wait. If the committee is quick and you’re lucky you’ll hear something after a few weeks (two or three, say); if you do not hear anything for more than six weeks, you are probably out of the game. In case you are lucky you will be invited for a job interview (sometimes by email, sometimes by snail mail and sometimes by phone). Usually there will be five to seven people invited. The job interview always takes place at the university you applied to (I think – I have never been asked for a phone or Skype interview). It always consists of

• research talk (between 30 and 45 minutes) and
• the actual interview with the committee.

Sometimes you will be asked to

• give a lecture for students

and I was once told that there will be an interview by students. It never happened to me that special meetings with other faculty, the dean or anybody else were planned neither I had special campus tours.

I will focus on the job interview here. Usually, the committee consists of some math professors (three to six or so), a PostDoc or PhD student, some students (about two) and some member of the non-scientific staff. Moreover, it may happen that some member of the university board is present.

The question almost always follow the general guideline: Research, projects, cooperation, teaching, administration.

What are your next goals for your research? Variations are: Where to do you see yourself and your research in five or ten years? What are the important issues in your field? Here you can use what you have talked about in your research talk (and you can prepare your talk such that it helps you here). Have something concrete and some more general vision.

What was your motivation to apply for this position? You should have a good reason (different from “I apply to every position I can find.”) and you should tell the commitee.

What are your experiences with third party funding? Usually the committee would like to hear that you know where to get money for research and that you know how that works.

What possibilities for cooperation do you see? I think this is a crucial point and I often put some effort in to find out what is happening in the math department, in computer science, in physics and in the engineering department. However, I think that it is quite difficult to judge if there is the possibility for cooperation by just looking at the research themes on the webpages. Sometimes they sound pretty interesting and related but then it turns out that goals are different. It also happens that there are possibilities for cooperation where you do not expect them (which happened to me here in Braunschweig). Hence, I am quite careful here.

What lecture did you teach, what would you like to teach and hoe does that fit in our system? While the first two parts are easy, I usually found it quite hard to figure out how some system work from the inspection of the webpages, Modulshandbüchern or Studienordnungen. However, I try to be prepared by looking for lecture in their system which I could give. Often you will be asked “What do you think about “service teaching?” (meaning something like “math for engineers”, “math for biology”,…). There is an obvious false answer here I don’t really know what is the sense of this question…

What is your experience with administration? Basically the same as for the “service teaching”-question. There is an obviously false answer.

For sure there are more standard question and probably I’ll add them as they come to my mind.

When the committee is through with their questions, you’ll will be asked it you have any. Have some! Ask about the library, the expected travel budget, if there are positions associated to the professorship, the IT administration, how many students are there, if there are plans for larger research projects,…

Finally, I briefly summarize what happens after the interview: After all job interviews are through, the committee will decide on a subset of the invited guys (I think three to five) and ask some “big shots” in the field for reports. and an the basis of this the committee will form a list (in most cases with three places, exceptionally a shorter list on two or even one, in rare cases with two people on the third place). This takes at least three weeks but can take up to several month. The list has to go through the university administration which may take another few weeks. Strictly speaking you’ll not be contacted unless you are on the first place. However, you can ask the head of the committee (by phone – I not sure if email is appropriate) what has happened to your application. In case you are not on the list, the first thing you’ll hear officially is that the position has be filled (which can be several month or even more that a year later).

 

Farewell Ulrich Tautenhahn

I learned today that Ulrich Tautenhahn passed away last year in October. Although he was not a colloborator of mine and I did not know him very well, I thought I could dedicate a small post to him. Ulrich Tautenhahn worked in inverse problems and regularization theory and I was especially interested in his work on parameter choice rules (a problem which, in my humble opinion, could get more attention, by the way). He was one of the early pioneers in inverse problems in the former GDR and wrote his PhD thesis on nonlinear inverse problems as early as 1980.If you go through his list of publications you will see that he worked on quite a lot of different aspects of inverse problems. His activity has increased lately and he also followed recent trends like regularization in Banach spaces and multiparameter regularization. Farewell, Mr. Tautenhahn.

 

Journals, prices, rankings and ratings

Lately quite a discussion about journals, publishing and ranking has started, also in the mathematical community. As an entry to the discussion on the role of journals you may consider the post “How might we get to a new model of mathematical publishing?” by Timothy Gowers (and the follow-up “A more modest approach”) and also some entries on nuit blanche or the post “The problem with journals”. Recently, I found that the International Mathematical Union (IMU) has started a blog on related issues: The Blog On Mathematical Journals. In the first entry “BLOG on Mathematical Journals” Ingrid Daubechies and Barbara Lee Keyfitz describe the aim of this blog: “We invite the mathematical community to provide their views on the journal rating issue, and on whether IMU and ICIAM should formulate their own rating. Views on how to establish and update this rating would also be welcome.” Although the first entry only introduced the rating issue, two further posts discuss other topics related to publishing: What might be done about high prices of journals? and Beyond Journals.

In total, the current system of publication is criticized to several extends in the discussion and I’d like to add some remarks on the pricing and ranking issue in this post.

1. Pricing

I know that some journals have prices which seem high and I have heard a lot of people complaining about high journal prices (some of them just repeat what they have heard, but other are in charge of library budget). I myself can not judge if prices are too high or appropriate. However, Where I am it seems like the library is not too rich, but basically I have no problems to obtain the papers I’d like to read: Either they are available in published digital form or printed (by campus or national license), they are available at the authors websites (in their published form or in a preprint form), they are available in preprint form on some preprint server or, as a last resort, I ask the authors directly (and rarely I ask a colleague at a richer university to download the paper and send it…). So, access to results is not a problem for me and I think for nobody at a university, at least in Germany.

One complain is that the countries pay the private publishers, through the university budgets, for work which is done by their employees (the scientists). Well, but this seems ok, since the scientists are the “only” customers, and the customers pay for what a company delivers to them. This is comparable to other situations in which countries pay private companies. However, here (as in other cases) a non-profit company, run by the country, could do the same job. A specific issue is that the journals are totally international (e.g. the editorial boards are mostly formed by reputation in the respective field and not by nationality). Hence, a centralized system should be independent of the countries which makes a transition from a decentralized system based on companies difficult.

Moreover, publishing is not totally for free and it just not true that publishers do nothing for their money. Well, we TeX our papers ourselves, however, a good publisher has to do (and does) quite some editing both technically and linguistically, to get a polished and publishable paper. Also, do not forget that the publishers do a good job in maintaining databases, permanent and stable links and cross-referencing their content (do not point to free tools like Google Scholar here, they heavily depend on the good databases by the publishers). For me it seems difficult to judge if journals are overpriced. I just do not have enough information: How many staff is needed to maintain the publication of a journal? How is the access to articles in general (several journals allow to publish a pdf on your own website)? What are examples of bad practice and best practice (high price with no service, high price and great service, low price and good service…)?

2. Ranking and rating

The primary task of the IMU blog is the discussion of journal ratings. I am not sure about the differences between “rating” and “ranking” but as far as I understand, a ranking of things should at least answer the question “Which of these two items is better?” for all two items, while a rating should answer the question “How good is this item?” for every item. Then, a ranking of journals is, in my opinion, truly not desirable and not achievable. Well, I am sorry for this old analogy, but this is just comparing apples and oranges. Which one is better: FC Barcelona or the LA Lakers? The Simpsons or How I met Your Mother? An iPad or a Nintendo 3DS? A Hummer H2 or a Smart? Lufthansa or the London Underground? Jacket or trousers? Annals of Mathematics or Annals of Statistics? Annales Scientifiques de l’École Normale Supérieure or Mathematics of Operations Research? SIAM Journal on Numerical Analysis or Crelle’s Journal? I hope you’ve got my point…

But how about a rating? Isn’t it possible to say that a journal is top, average or below? Actually there is journal rating by the Australian Mathematical Society here (although they call it ranking…). There they rate the journals into categories A*, A, B and C (from good to bad). I checked the rating of some journals I know and published in and I have to confess that I mainly agree with the ratings of there journals (e.g. Inverse Problems is excellent, Current Development in Theory and Applications of Wavelets is mediocre).

There are a lot of comments to the post BLOG on Mathematical Journals most of them saying that it is inappropriate to reduce the “quality” of a journal to a single number or rate and this number will not be any better than Impact Factor rubbish (see e.g. the comment by Jean-Paul Allouche). Arieh Iserles made the point that ratings are already used and will be used in the future and a self-made rating will be better than the others. John Ball argues why arguing against all rating is the better alternative (and gives two examples in which organizations abandoned from using ratings or bibliometry).

Basically, I do not have to add anything new to the comments given in the post. My opinion is that rating is possible but both useless and dangerous. It is possible, since you can ask experienced mathematicians and you will get a reliable answer. It is useless, since you either know which journals are good or you can ask a colleague (which is basically the same reason as the previous one). It is dangerous, since it offers the possibility to form decisions on tenure or grants on these numbers and shifts the focus from what you publish to where you publish (see also the comment by Ivar Ekeland to this post).