Tomography 203

This video illustrates “ill-posedness”, the nemesis of all inverse problems. We see how in a very simple 12×12 pixel tomography problem “almost-ghosts” can produce very different targets with almost the same X-ray data.

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Tomography 201: tomography by pixels

I started a new video series in my all-English YouTube channel called “Professor Sam”. Today’s upload is Tomography 201: tomography by pixels, which introduces the need for iterative variational regularization in tomographic image reconstruction with sparsely collected data. This 200-series of videos is a continuation of the 100-series explaining the basics of tomography.

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Tomography 104: simulating sinograms

I just published a new video in my lecture series on X-ray tomography (link). There I show how to use Matlab to simulate basic tomographic things such as sinograms and filtered back-projection algorithms. I also give an introductory discussion of measurement noise and how to supress it with a low-pass filter. This is how it

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Samuli Siltanen esitelmöi New Yorkin matikkamuseossa

Math Encounters NYC video

I gave a talk in the “Math Encounters” series at the Museum of Mathematics in New York City in February 2023. My topic was X-ray tomography. Now the video recording of the presentation is available! Enjoy!

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Nice workshop in Cambridge

I co-organized a workshop in March 2023 at the Isaac Newton Institute in Cambridge: It was so nice to see many colleagues after a long break! Instead of a regular scientific talk, I gave a presentation by title “Science Showmanship”. It contained some scientific stand-up comedy and stories about being a mathematical YouTuber. In

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X-ray Tomography 103: new video

My entertaining, yet scientifically accurate video series continues. It’s my educational experiment with material that serves both science popularization and academic teaching. Enjoy!

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Happy Pi Day!

I made a fun X-ray tomography video about pi. Enjoy! (And make sure to subscribe to my channel Professor Sam)

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Physics experiment

Convolution, Part 1: filters, signals and boiling water

This video starts my lecture series on the mathematical concept of convolution. The lecture is part of my course “Inverse Problems 1: Convolution and Deconvolution” that I currently teach at University of Helsinki, Finland. I am a professor of Industrial Mathematics at UH.

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