Josua Sassen

Postdoc in Mathematics @UniBonn @HCM_Bonn. Working on variational problems in Geometry Processing. Also: @[email protected]

[Josua Sassen @jrsassen]

@ZorahLaehner Thank you! Not on arxiv, but you can read it on OpenReview: https://t.co/DMDwARY8Te

[Josua Sassen @jrsassen]

Starting into the weekend with the message that our paper on approximating Riemannian shape manifolds was accepted at #ICLR2023 (even notable-top-25%) has been great!
A big thanks to my co-authors: Klaus Hildebrandt, Benedikt Wirth, and Martin Rumpf. More details coming soon!

[Josua Sassen @jrsassen]

@AntoPatriarca @amirvaxman_dgp Well, it can if you only ask for C1-regularity: https://t.co/GM4s8hpkZB
But it has no defined Gauß curvature

[Josua Sassen @jrsassen]

@nervous_jesse @nmwsharp @BrunoLevy01 @HerholzPh @MenyJanos I played around a bit with a simple multiphase model in FEniCS. Seems to work.
Here I optimize three phases with a penalty for each to cover 1/3 of the domain. I used constant Gauß curvature, i.e. basically considered a patch of a sphere.

[Josua Sassen @jrsassen]

@nervous_jesse @nmwsharp @BrunoLevy01 @HerholzPh @MenyJanos I played around a bit with a simple multiphase model in FEniCS. Seems to work.
Here I optimize three phases with a penalty for each to cover 1/3 of the domain. I used constant Gauß curvature, i.e. basically considered a patch of a sphere.

[Josua Sassen @jrsassen]

@nmwsharp @BrunoLevy01 @nervous_jesse @HerholzPh Our phase-field version of variational cutting avoids actually cutting the mesh: https://t.co/XgIAqJLBF5
Still needs multiple linear solves, but I guess they could be done quickly with preconditioned CG.
@MenyJanos has code and a web version available: https://t.co/dO7SH5w5gd

[Josua Sassen @jrsassen]

@nervous_jesse @nmwsharp @BrunoLevy01 @HerholzPh @MenyJanos Thanks! What should be doable is optimizing all levels of the hierarchy at the same time. Dynamically changing the hierarchy itself is, I guess, not really feasible.
We didn't look at other multiphase models yet, but the general diffuse Yamabe approach should be transferable.

[Josua Sassen @jrsassen]

@nervous_jesse @nmwsharp @BrunoLevy01 @HerholzPh @MenyJanos Sure! You can find our PDF here: https://t.co/JN8QWYye1A

[Josua Sassen @jrsassen]

@nmwsharp @BrunoLevy01 @nervous_jesse @HerholzPh Our phase-field version of variational cutting avoids actually cutting the mesh: https://t.co/XgIAqJLBF5
Still needs multiple linear solves, but I guess they could be done quickly with preconditioned CG.
@MenyJanos has code and a web version available: https://t.co/dO7SH5w5gd

[JAMA Ophthalmology @JAMAOphth]

Study supports the validity of reading performance as endpoint in clinical trials and suggests that measures in clinical and low vision care of patients with geographic atrophy secondary to AMD should focus primarily on the better-seeing eye https://t.co/AY8Ksh5nWD

[LOGML Summer School @LogmlSchool]

Last speaker of the week! Can you believe it? Prof. Dr. Martin Rumpf from @UniBonn talks about Sparse PCA on Shape Manifolds! https://t.co/DL9OBOGhlh

[Josua Sassen @jrsassen]

@JustinMSolomon Yesss, I see my package.. Can't wait to get it! 🦾 Thanks for the hard work!!

[Josua Sassen @jrsassen]

@amirvaxman_dgp Ah, I meant applying CG to the penalty problem. This I think you could also combine with line search.

[Josua Sassen @jrsassen]

@JustinMSolomon Alg. 2 in https://t.co/DuZGxFbBaJ uses at least the max-oracle. Although not both or at least the (cheaper?) min-oracle. However, maybe a step in the right direction.

[Alan Zucconi @AlanZucconi]

You might have heard that Conway's Game of Life is Turing complete.

But what most people who are familiar with the game don't know, is what that *truly* entails.

That it is possible to create Life ...within Life itself. ⠠⠵

https://t.co/25VnfCmTe9

[𝘁𝗶𝗺 𝗯𝗮𝗿𝗻𝗲𝘀 @TimBarnes451]

Enlightenment, but it's behind a paywall

[Alec Jacobson @_AlecJacobson]

All 16 SGP 2020 Graduate School instructors (including me) are men. This extreme lack of gender diversity does not reflect the geometry processing community

Let's talk about diversity at the townhall on Tuesday

meanwhile, let's post great geometry processing papers by women:

[Josua Sassen @jrsassen]

@_AlecJacobson Thanks! Recording it was actually a lot of fun. Although I'm not looking forward to cleaning up the living room..

I'm also stoked to watch all the other presentations!

[Alec Jacobson @_AlecJacobson]

um... wow!

I'm super impressed with the quality of the SGP Technical Paper presentation videos.

Find youtube playlists here: https://t.co/4BBVZuFn8z

And check out the production value of this one by Josua Sassen:
https://t.co/t9gPfTsoux