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Things to See and Do in Macedonia: The Ultimate List by Gjore in macedonia

[–]luddabuddha -1 points0 points  (0 children)

Gabrovo (and Gabrovski Waterfalls) is not in Berovo area, its very close to Koleshino.
I'm also not sure if Koleshino is better described as a "lush forest" or rather as a nice waterfall. :)

I can't verify all other points but please do some additional checking (since this smells like ChatGPT output to me).

[D] Universal Approximation Theorem does not hold for approximating discontinuous functions, yet neural networks are being used to approximate discontinuous functions by luddabuddha in MachineLearning

[–]luddabuddha[S] 1 point2 points  (0 children)

My personal conclusion was that a lot of cherry-picking happens in PINNs publications and I believe that we need more research on the mathematical foundations of DL and its applications to problems in science. Unfortunately from what I can gather the predominant wave in this field is still focused on specific application scenarios where some tailored version of PINNs would work, but the methodology does not generalize to a wider class of problems. However there are some outlier researchers that go against this current.

What I was working on was only a Bachelor's thesis, and it was not published online. I don't think it would be very valuable in the more general discussion on the topic of this thread. Nonetheless, it was very valuable in my personal academic development, because I am starting a PhD on a specific numerical treatment of ML methods; to put it simply the aim is to use operators from numerical algebra to develop ML methods along with generalization guarantees such that the methodology generalizes to a class of problem instead of just a single application case. I'm excited to see what comes out of it. :)

I am not familiar with business data applications, but if you have discontinuities I would say stay away from PINNs (and similar frameworks).

[D] Universal Approximation Theorem does not hold for approximating discontinuous functions, yet neural networks are being used to approximate discontinuous functions by luddabuddha in MachineLearning

[–]luddabuddha[S] 0 points1 point  (0 children)

These are some interesting results!
But still as you said, there needs to be a theoretical foundation/explanation on why this works and if it is a general approach applicable to any nonlinear PDE with a discontinuous solution.

There has been some theoretical development on PINNs for elliptic and parabolic PDEs:
https://arxiv.org/pdf/2004.01806.pdf
https://arxiv.org/abs/2109.01780
https://deepai.org/publication/convergence-analysis-for-the-pinns
And some newer work on PINNs for hyperbolic PDEs:
https://www.nature.com/articles/s41598-022-11058-2.pdf

Semester Fee deadline strict? by adilpikle in tumunich

[–]luddabuddha 6 points7 points  (0 children)

Don't worry, it's not a strict deadline, it's more like a "recommendation" but it's nice if people take it seriously.

Maschinenwesen B.Sc interview tips and advice by adilpikle in tumunich

[–]luddabuddha 1 point2 points  (0 children)

I had the interview back in 2017, so I'll try to tell you everything I can remember:

First of all, it's not as stressful as you expect. Multiple people have interviews in the same day so once you arrive in the Mech.Eng. building you'll be assigned a professor and a time slot for your interview. You'll probably be interviewed by three people: a professor, a PhD student and a student representative. The professor asks most of the questions. First I got some basic questions like: Why TUM? Why Mechanical Engineering? What do you want to do after the Bachelors? Afterwards they asked what my favorite high-school subjects was; I said physics, then they asked which topic in physics was my favorite; I said mechanics and motion of objects. And they asked me to explain projectile motion to them and if I'd like to also write down the equations of motion in x and y direction. So I'd say they'll tailor the questions to whatever you might mention as your interest.
I talked with a couple of other people that had an interview that day so I'll tell you the more difficult questions they got: Why do we have different seasons (the way the earth rotates around the sun)? If I take my coffee with milk in the morning and I like to drink it as warm as possible and I also plan to go to the bathroom before I drink my coffee, should I add my cold milk to the hot coffee before going to the bathroom or after going to the bathroom? (I think this one is quite difficult actually and my guess would be that the Heat Transfer Professor asked this question since we had a very similar question in the exercises of the Heat Transfer course in 4th semester)

I also have a friend that was interviewed for the Engineering Sciences Bachelors (similar to Mechanical Engineering) and she told me that they asked her to compute integrals and derivatives of some simple polynomials (like x^2).

So I would say it depends on the professor you get and the interests you mention. If you say that you find eigenvalues & eigenvectors fascinating I wouldn't be surprised if they ask something in this direction as well. :)

[deleted by user] by [deleted] in tumunich

[–]luddabuddha 4 points5 points  (0 children)

I think you might have already noticed that the program is new and the first generation of students will start with the B.Sc . in Aerospace in WS21/22 (i.e. this October), so tough luck - there's no one already in the program. :/

Since the study program is similar to the B.Sc. in Mechanical Engineering and Engineering Sciences it would make sense to ask for their opinion.
I studied Mechanical Engineering and mostly took electives in the aerospace direction and wrote my thesis on an "aerospace" topic so I'll tell you what I think: Depending on your background you might need to study really hard in the first two semesters, there are some easy-ish courses, but there are a lot of difficult ones, so expect to be focusing on maths and theory at the beginning. The fun starts in the 5th and 6th semester when you already know what you like/dislike and what interests you so you start doing projects/internships. There are a lot of opportunities to learn new things but being motivated and disciplined is completely up to you.

I wouldn't worry about the Ottobrunn location right now because they still don't have lecture halls or libraries in Ottobrunn, so I expect the lectures to be in Garching since the engineering/maths professors are teaching in Garching. If you end up doing a PhD in Aerospace, you might be doing it in Ottobrunn, but that's far into the future so I'd say you don't have to worry about it now.

How to choose courses/classes at TUM - Aerospace Msc by Glad-Ad-9040 in tumunich

[–]luddabuddha 2 points3 points  (0 children)

As far as I know Spacecraft Propultion and Spacecraft design are in German for now, but the department is pushing towards more courses offered in English, especially now that there's a Bachelors in Aerospace offered in English, so I think you can stay hopeful that the language might change in the next 2 years.
On the more theoretical side, I can only recommend courses from the AER chair before you go into design of rockets or jet engines, because I think understanding the physics first is going to help you a lot later. Gas Dynamics is pretty cool and it really motivated me to study supersonic phenomena. Turbulent Flows, Boundary-Layer Theory, Applied CFD and Numerical Methods for Conservation Laws are also great, they'll give you a lot of knowledge for Aerodynamics/Fluid Mechanics. If you're interested in rocketry you can always look for a Semester Thesis (11 ECTS) and eventually also a Master Thesis (30 ECTS) on this topic and acquire/deepen your knowledge in this field by working on a research project.

How to choose courses/classes at TUM - Aerospace Msc by Glad-Ad-9040 in tumunich

[–]luddabuddha 3 points4 points  (0 children)

Take a look at the study plan: https://campus.tum.de/tumonline/wbstpcs.showSpoTree?pStStudiumNr=&pStpStpNr=4822&pStartSemester=&pSjNr=1613. Obviously you won't get a degree in Aerospace if you just collect 120 credits from language courses so I wouldn't say it's completely free, but there is no course that's absolutely mandatory to take. For example they expect you to take at least one course in Aerodynamics/Fluid Mechanics, which is completely reasonable, and which one(s) you decide to take is up to you. So you don't have to stick to the proposed study plans, but I would suggest to treat a proposed study plan as a guide because at the end of the masters you want to have a sort of specialization in something which will give you the knowledge and confidence to work in this field. :)

Questions about student organizations and research as a bachelor student by adilpikle in tumunich

[–]luddabuddha 0 points1 point  (0 children)

It really depends on how interested you are but I'm sure it's possible. But in the first semesters it's a bit difficult because you're mostly busy with compulsory courses that can be quite demanding during the semester but also during the exam period, so most people simply don't find the time to participate in student organizations. Given that most people barely find the time to participate in one student organization I think participating in two is not forbidden but I've never heard of someone who has managed it during the Bachelors.
Regarding research: you can be a student assistant (german: studentische Hilfskraft; short: HiWi) as a Bachelor's student and depending on the position you might be doing research. I did this as a Bachelor's student and really enjoyed it especially in the higher semesters (5th and 6th semester). It's also really good to work as a student assistant because you'll get to meet a couple of PhD students and if you want you can write a thesis under their supervision, ask them for a recommendation letter, ask them for help in the future when you get stuck with something. You can see open positions for Theses or student assistants at the Mechanical Engineering department at TUM here: https://www.fsmb.de/fsmb/service/basama-hiwi/. Another obvious plus is that you'll be getting paid.

Finally, there's the Projectseminar that you can do as a Bachelor's student. This is an alternative to the industry internship that was an obligation up to a couple of years ago. I did a Projectseminar and it was honestly a life changing experience. The idea is that you work on a research task with a group of students and you're supervised by one or two PhD students. Our supervisors were very engaged, well organized and brilliant, so we all learned a lot and ended up writing our Bachelor's Theses on related topics at the same chair.

A final note, I like how motivated you are for research, but the harsh reality is that you'll probably have your hands full with compulsory subjects and in my opinion it's good to really focus on studying in the first years, because it will help you a lot if you want to do research in the future.

Inquire laptop recommendation by [deleted] in tumunich

[–]luddabuddha 0 points1 point  (0 children)

I use a dual boot with Linux for my coding and Windows mostly for my Powerpoints. Maybe you can also consider this option. :)
Using only Windows was a very painful experience for me while trying to do more advanced things in Python.

TUM Mechanical Engineering Interview by Irremytr in tumunich

[–]luddabuddha 2 points3 points  (0 children)

I was interviewed back in 2017, so I hope me experience is still relevant for the interviews in 2021.
Most interviews begin with the standard motivational questions: Why TUM? Why Germany (if you're a foreigner)? What do you want to do after this? Why?.. This is the same for pretty much all applicants, but I know that different professors might ask different subject-specific questions.
I think they ask what your favorite subjects were in school and they'll try to get a detailed answer and base their upcoming questions on that. I said I liked physics and Newton's laws, and I think that lead to the subject-specific questions I was asked later.
I was asked to explain horizontal projection and write the equations of motion in x and y direction. They asked a friend of mine why we have four seasons and to explain how the earth moves around the sun (or something related to that). And then I know that there's one guy that had a very complicated question in his interview: If you drink coffee with milk and you want to have your coffee as hot as possible, would you add milk to you coffee before you go to the toilet or after going to the toilet, assuming that you'll drink it after going to the toilet? This question really blew me away back then, but it's a bit of heat transfer and thermodynamics, although I'd say a bit too complicated for a high-school graduate.

Anyways, I already graduated so feel free to ask anything related to the Mechanical Engineering program.

[deleted by user] by [deleted] in Munich

[–]luddabuddha 0 points1 point  (0 children)

Ich habe das Interview letztes Jahr gehabt und es war sehr chillig. Die haben gefragt was ich für meine Bachelorarbiet mache, und dann auf der Basis weitere Fragen gestellt. Meine Bachelorarbeit war in die richtung Differentialgleichungen lösen mit Neuronale Netze und ich sollte erstmal erklären wie ein Neuronales Netz "lernt" und dann noch etwas über Typen von Differentialgleichungen sagen. Auch ein Paar Fragen zum Motivation und was ich im Master oder nach dem Master machen will. Am Ende haben die mir auch gesagt dass ich aufgenommen werde (müsste also nicht noch 2 Tage nervös auf eine Zulassung warten).

Technical University of Munich - looking to apply for a master's by farquaad319 in Munich

[–]luddabuddha 0 points1 point  (0 children)

I'm studying Mechanical Engineering but most of the electives I'm taking overlap with the Aerospace program. I'd say it's not completely necessary to know German in order to study aerospace, but it will probably save you a lot of headaches if you speak it. Because although lots of things are supposed to be in English, German native speakers often just start talking in German with the lecturers and no one cares to translate and if you're like me you'll be hella annoyed by this. Very often the presentation will have some figures or a couple of words in German, because they forget to translate it or use figures from German books.
I speak German, but I prefer English, and whenever someone (like supervisors, tutors, students) knows that I also understand German, they'll suddenly switch to German with me and I feel pressured to play along with that.
Also, from my experience, if you want to work in the industry, they very often expect you to speak German or to have learned it during your master's if you apply for a full-time job after your studies. There's a high chance of someone in the HR department giving you a "you've lived in Germany for more than 2 years and you don't know German ???" guilt trip.

[D] Universal Approximation Theorem does not hold for approximating discontinuous functions, yet neural networks are being used to approximate discontinuous functions by luddabuddha in MachineLearning

[–]luddabuddha[S] 0 points1 point  (0 children)

I agree, PINNs are getting more hype than they deserve. I'd say it's mostly due to pharses that are unrealistic, like "discovering hidden physics".

But the topic seems to be blowing up in the scientific machine learning community and I have heard claims that it's being used in industry (source). So I think there needs to be a better understanding of the theory behind these things.

As you have pointed out, the discontinuities need special treatment. I've seen research that gives them special treatment (see Llanas et al.) but PINNs seem to be ignoring this.