Marcel Hussing's Avatar

Marcel Hussing

@marcelhussing.bsky.social

PhD student at the University of Pennsylvania. Prev, intern at MSR, and Meta FAIR. Interested in reliable and replicable reinforcement learning, robotics and knowledge discovery: https://marcelhussing.github.io/ All posts are my own.

2,959 Followers  |  336 Following  |  179 Posts  |  Joined: 09.11.2024
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Posts by Marcel Hussing (@marcelhussing.bsky.social)

Why are you doing this to me

26.02.2026 17:32 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

I think it's relatively simple. One side already has the job they want and the other side needs citations to get that job. And everyone tells me advertising work is how you get citations. I have been tempted to go back because on bsky, interactions have become fewer and fewer. Not going to though...

16.02.2026 15:01 โ€” ๐Ÿ‘ 6    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Yet somehow every now and then a paper becomes very popular even though its findings are similar to those of many others. This paper gets cited while the others don't. Was it just luck?

15.02.2026 02:43 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

While I agree with the sentiment let me play devil's advocate. You only get invited to give talks if your work is already well known. Conferences have become too large to even find relevant people. And social media posts are only marginally relevant if you don't already have a large following.

15.02.2026 02:40 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 0

I understand that that is okay but at some point it honestly becomes disheartening if you constantly have to reach out to people. There are others who don't seem to have to; what are they doing differently?

14.02.2026 23:32 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Iโ€™m trying to understand whether this is mostly about keyword mismatch, venue visibility, social media, etc.
For example, when I search terms like โ€œhigh update ratio RLโ€ on Scholar, our papers show up near the top.

scholar.google.com/scholar?hl=e...

Where are things going wrong?

14.02.2026 23:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Iโ€™ve been thinking about a practical question and would love some opinions:

How do your papers actually get discovered/cited?

I was searching for recent work on high update ratio RL and found several very closely related papers tackling the same failure modes we study. None cited our earlier work.

14.02.2026 23:13 โ€” ๐Ÿ‘ 9    ๐Ÿ” 2    ๐Ÿ’ฌ 5    ๐Ÿ“Œ 0

๐Ÿš€ Excited to share REPPO, a new on-policy RL agent!

TL;DR: Replace PPO with REPPO for fewer hyperparameter headaches and more robust training.

REPPO, led by @cvoelcker.bsky.social, will be presented at ICLR 2026. How does it work? ๐Ÿงต๐Ÿ‘‡

13.02.2026 19:28 โ€” ๐Ÿ‘ 25    ๐Ÿ” 10    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Scaling Laws in Particle Physics Data! This is a result I've been itching to share and it's finally out. One of the big open questions is how much better AI-based methods at particle colliders can still become. 1/4

01.02.2026 11:55 โ€” ๐Ÿ‘ 16    ๐Ÿ” 7    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 0

Not a particle physics person but extremely curious, can you elaborate what we might hope to learn from these models in the future? What physics might we discover using them?

01.02.2026 20:36 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

"Scientific reviewers should have experience publishing scientific work in related areas" is really not that hot of a take.

27.01.2026 15:25 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1

Clicking like on any relevant ICLR paper. Encourage people to post their work here more!

26.01.2026 16:32 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

How do I see this?

26.01.2026 16:22 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

The other paper accepted to @iclr-conf.bsky.social 2026 ๐Ÿ‡ง๐Ÿ‡ท. Our work on replicable RL sheds some light on how to consistently make decisions in RL.

@ericeaton.bsky.social @mkearnsphilly.bsky.social @aaroth.bsky.social @sikatasengupta.bsky.social @optimistsinc.bsky.social

26.01.2026 16:08 โ€” ๐Ÿ‘ 13    ๐Ÿ” 5    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Two papers accepted to @iclr-conf.bsky.social 2026! One of the is REPPO, see below! I think it deserves a lot more recognition. Let's chat about it in Rio! ๐Ÿ‡ง๐Ÿ‡ท

26.01.2026 16:05 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Quite disheartening that there isn't a single workshop at ICLR to present my RL work but there several topics that are listed 5 or 6 times just named differently.

26.01.2026 19:17 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

That's correct, we did make it bold

24.01.2026 03:46 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Our number went down by 0.01 but it's very expensive to run so we can't have error bars. Our algorithm is so much better than the rest, new SOTA!

23.01.2026 14:46 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

I can't believe that this paper is not yet used by literally everyone. Claas doing all he can to make your life easier. Check it out.

17.01.2026 22:06 โ€” ๐Ÿ‘ 3    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Bringing this back up.

13.01.2026 11:36 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Excited about a new paper! Multicalibration turns out to be strictly harder than marginal calibration. We prove tight Omega(T^{2/3}) lower bounds for online multicalibration, separating it from online marginal calibration for which better rates were recently discovered.

09.01.2026 13:21 โ€” ๐Ÿ‘ 21    ๐Ÿ” 3    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

For me, it's mostly verbalizing code I already know I want. I don't write whole apps. I take my RL code and add entropy regularization to TD3. Then I verify. Be explicit about what needs to change and know ahead what changes you expect. I still do the thinking, I just worry less about code context.

26.12.2025 00:24 โ€” ๐Ÿ‘ 5    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

I like this site a lot but too few people are posting interesting ML content imo and if they do too infrequently. I realize this for myself a lot.

22.12.2025 19:41 โ€” ๐Ÿ‘ 6    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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A Multi-Robot Platform for Robotic Triage Combining Onboard Sensing and Foundation Models This report presents a heterogeneous robotic system designed for remote primary triage in mass-casualty incidents (MCIs). The system employs a coordinated air-ground team of unmanned aerial vehicles (...

This project is a huge team effort across @grasplab.bsky.social and Penn trauma led by PIs @ericeaton.bsky.social and CJ Taylor. Shoutout to @jasonahughes.bsky.social, Raj Kannapiran, and Edward Zhang who did a lot of the heavy lifting. Check out the technical report arxiv.org/abs/2512.08754 (5/5)

22.12.2025 18:50 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Then the ML takes over. Onboard models estimate breathing and heart rate from radar and thermal, and read injuries from multi view images and audio. Fine tuned VLMs plus Grounding DINO and SAM2 convert data into a triage report for responders. (4/5)

22.12.2025 18:50 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Our robots do the dangerous first pass. Falcon drones sweep the scene from above using RGB and thermal cameras to detect and geolocate casualties in day or night. Jackal ground robots then drive in for close up sensing and send a live victim map to responders. (3/5)

22.12.2025 18:50 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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In this project, we are building a multi-robot system to facilitate the process of triage. The system consists of a fleet of Jackal ground robots and several in-house built Falcon drones which rapidly scan an area, localize people in need and help determine their injuries. (2/5)

22.12.2025 18:50 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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In emergencies, minutes can decide who lives and who dies. Our team is participating in the Triage Challenge, building AI to empower clinicians and prioritize care when resources are thin:
prontotriage.com

Also recently featured by Meta:
ai.meta.com/blog/upenn-d...

(1/5)

22.12.2025 18:50 โ€” ๐Ÿ‘ 3    ๐Ÿ” 2    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Posted about this last week; I feel like it didn't get as much attention as it deserves. We have a new preprint on using diffusion models to generate compositional data. This work was conducted by Quan, a student I advised over the fall. He is currently looking for PhD positions. Check it out!

22.12.2025 15:57 โ€” ๐Ÿ‘ 5    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Oh nice, this is kinda cool. Have an immediate idea on what to do with this. :D Hadn't heard of this before. Which ones are the most interesting multi-player games available and for what reason do you think they are interesting? I'm assuming those are multi-agent games?

19.12.2025 18:41 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 4    ๐Ÿ“Œ 0