SCCS Kolloquium

The SCCS Colloquium is a forum giving students, guests, and members of the chair the opportunity to present their research insights, results, and challenges. Do you need ideas for your thesis topic? Do you want to meet your potential supervisor? Do you want to discuss your research with a diverse group of researchers, rehearse your conference talk, or simply cheer for your colleagues? Then this is the right place for you (and you are also welcome to bring your friends along).

Upcoming talks

Angelos Nikitaras: Solving least-squares problems involving large dense matrices

SCCS Colloquium |


With the advent of Deep Learning, training large-scale neural networks has become a crucial task across a wide range of applications. Typically, the training is performed using gradient-based optimization algorithms, with the most popular being Stochastic Gradient Descent and its variants. Random feature models offer a different method for training neural networks, where the parameters of the hidden layers are sampled from a data-agnostic distribution, such as a normal distribution. Building on this concept, a novel approach, known as the Sampling Where It Matters (SWIM) algorithm, was recently proposed. In SWIM, the network parameters of the hidden layers are constructed using a data-driven sampling scheme, followed by solving a linear least squares problem for the output layer. This linear problem is dense and highly ill-conditioned, posing significant challenges for traditional numerical solvers.


In this work, we investigate numerical methods for solving the least-squares problems that arise in the context of the SWIM algorithm, with a focus on scalability and efficiency. We propose using a recently developed iterative solver called LSRN, which leverages randomized preconditioning to significantly improve the convergence rate. In addition, we introduce an alternative approach that divides the problem into smaller subproblems, which are solved sequentially. We demonstrate the effectiveness of these methods through a series of numerical experiments, showcasing substantial improvements in training speed and scalability.

Guided research presentation. Angelos is advised by Prof. Dr. Felix Dietrich.


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Contribute a talk

To register and schedule a talk, you should fill the form Colloquium Registration at least four weeks before the earliest preferred date. Keep in mind that we only have limited slots, so please plan your presentation early. In special cases, contact colloquium@mailsccs.in.tum.de.

Colloquium sessions are now on-campus. We have booked room MI 00.13.054 for WS24/25. You can either bring your own laptop or send us the slides as a PDF ahead of time. The projector only has an HDMI connection, so please bring your own adapters if necessary.

Do you want to attend but cannot make it in person? We now have a hybrid option. Simply join us through this BBB room: https://bbb.in.tum.de/shu-phv-eyq-rad

We invite students doing their Bachelor's or Master's thesis, as well as IDP, Guided Research, or similar projects at SCCS to give one 20min presentation to discuss their results and potential future work. The time for this is typically after submitting your final text. Check also with your study program regarding any requirements for a final presentation of your project work.

New: In regular times, we will now have slots for presenting early stage projects (talk time 2-10min). This is an optional opportunity for getting additional feedback early and there is no strict timeline.

Apart from students, we also welcome doctoral candidates and guests to present their projects.

During the colloquium, things usually go as follows:

  • 10min before the colloquium starts, the speakers setup their equipment with the help of the moderator. The moderator currently is Ana Cukarska. Make sure to be using an easily identifiable name in the online session's waiting room.
  • The colloquium starts with an introduction to the agenda and the moderator asks the speaker's advisor/host to put the talk into context.
  • Your talk starts. The scheduled time for your talk is normally 20min with additional 5-10min for discussion.
  • During the discussion session, the audience can ask questions, which are meant for clarification or for putting the talk into context. The audience can also ask questions in the chat.
  • Congratulations! Your talk is over and it's now time to celebrate! Have you already tried the parabolic slides that bring you from the third floor to the Magistrale?

Do you remember a talk that made you feel very happy for attending? Do you also remember a talk that confused you? What made these two experiences different?

Here are a few things to check if you want to improve your presentation:

  • What is the main idea that you want people to remember after your presentation? Do you make it crystal-clear? How quickly are you arriving to it?
  • Which aspects of your work can you cover in the given time frame, with a reasonable pace and good depth?
  • What can you leave out (but maybe have as back-up slides) to not confuse or overwhelm the audience?
  • How are you investing the crucial first two minutes of your presentation?
  • How much content do you have on your slides? Is all of it important? Will the audience know which part of a slide to look at? Will somebody from the last row be able to read the content? Will somebody with limited experience in your field have time to understand what is going on?
  • Are the figures clear? Are you explaining the axes or any other features clearly?

In any case, make sure to start preparing your talk early enough so that you can potentially discuss it, rehearse it, and improve it.

Here are a few good videos to find out more:

Did you know that the TUM English Writing Center can also help you with writing good slides?

Work with us!

Do your thesis/student project in Informatics / Mathematics / Physics: Student Projects at the SCCS.