NicoleCRust, (edited ) to random
@NicoleCRust@neuromatch.social avatar

Looking for: complex systems that defy model reduction.

The behavior of a complex system is hard to predict from its parts alone because it follows from how the parts interact.

Model reduction is a way to capture the behavior of a complex system more simply (eg to capture the magnetism of 1g of Fe2O3, you don't have to model all 1022 molecules and their interactions). My sense is that model reduction works best when you have many repeated copies.

I'm looking for some good (ideally concrete) examples of complex systems that defy model reduction. I anticipate that they will be made of heterogeneous parts.

Thanks in advance!

nielspflaeging, to random

I sometimes explain to people why the so-called "Cynefin model" is utter crap. I usually start by giving them 1 very simple fact that is false about Cynefin. False as in blatantly wrong. Then something strange happens: People who "use" that model do not reflect, do not get thoughtful, they do not even argue!

Instead, they start talking about how they use that instrument and that it is "still useful". That it "makes people think".
See the irony?

https://www.linkedin.com/pulse/curse-double-axis-chart-niels-pflaeging

janriemer, to rust

To all people, who think 's syntax is ugly: maybe you should give this one a read:

Complexity Has to Live Somewhere - by Fred Hebert (discovered through @algo_luca's book):

https://ferd.ca/complexity-has-to-live-somewhere.html

"If you're unlucky and you just tried to pretend complexity could be avoided altogether, it has no place to go in this world. But it still doesn't stop existing."

dderigo, to random

1/

book [1] by @deevybee "As we shall see, demonstrating that an intervention has an impact is much harder than it appears at first sight"

https://mastodon.social/@deevybee/110118670777140484

"Much of the attention of methodologists has focused on how to recognize and control for unwanted factors that can affect outcomes of interest. But psychology is also important: it tells us that own human biases can be just as important in leading us astray"

NicoleCRust, to Neuroscience
@NicoleCRust@neuromatch.social avatar

My new piece for @thetransmitter. Why is treating brain dysfunction so ENORMOUSLY challenging?

Because it amounts to controlling a complex system.

Drawing from the history of weather research, I pose the question: Can it even be done? And 14 experts in complex systems chime in. Would love to hear your thoughts as well!

https://www.thetransmitter.org/systems-neuroscience/is-the-brain-uncontrollable-like-the-weather/

NicoleCRust, to Neuroscience
@NicoleCRust@neuromatch.social avatar

JUDICIOUS MODEL ROBUSTIFICATION

Reading George Box's 1979 paper that gave rise to the famous phrase "All models are wrong but some are useful."
https://www.sciencedirect.com/science/article/abs/pii/B9780124381506500182

That phrase is just so great. It's easy to see how it's counterpart slipped through the cracks. "Judicious model robustification" - who can claim not to aspire to that as well?

To all modelers out there, may your model be judiciously robustified!

matthewskelton, to random
@matthewskelton@mastodon.social avatar

"That impulse to scour away the messiness that makes life resilient is what many conservation biologists call the “pathology of command and control.” Today, the same drive to centralize, control and extract has driven the internet to the same fate as the ravaged forests."

We Need To Rewild The Internet
By MARIA FARRELL AND ROBIN BERJON

https://www.noemamag.com/we-need-to-rewild-the-internet/

toxi, (edited ) to genart
@toxi@mastodon.thi.ng avatar

One more from the heap of raw ideas and unfinished projects: This one from almost precisely 2 years ago, going under the working title "Computational Lace", but really a kind of fractal process based on an initial 2D SDF, creating a surprising amount of complexity from even the simplest seed shapes...

This is again one of these projects requiring a full size view to appreciate the fine structures emerging...

1/x

#GenerativeArt #Fractal #SDF #Monochrome #Lace #Morphing #Complexity #Emergence

franco_vazza, to random
@franco_vazza@mastodon.social avatar

So yesterday this happened: I was kindly invited to join and present the closing of an awesome art exhibition by Carolina Lombardi "Knitting chaos" in Rome,
https://www.google.com/amp/s/www.raicultura.it/amp/arte/articoli/2023/11/Carolina-Lombardi-Ricamando-il-Caos-eada785c-336f-4056-bbfe-0f42cfd8a5ff.html
all about visualisations of networks composed by the artist using string of words: an opera which took years to make! Also, stunning visualisation of the expansion dynamics of slime mold samples grown and photographed by the author.

I was asked to show some parallel complex networks in

anna, to foss
@anna@mathstodon.xyz avatar

Last week, I presented the work I did with prof. Kuldeep Meel and prof. Arunabha Sen at IJCAI 2023.

We showed the benefits of reducing a problem to a computationally harder problem (yes, you read that right!), by demonstrating how it allows us to solve much larger problem instances.

It was so much fun to finally share this work with so many fantastic researchers at IJCAI! Thank you to all organisers for making this conference possible. I'm also super grateful to the reviewers who gave us great feedback!

Please find our paper, slides, poster, a short video, and our open source tool, gismo, here: www.annalatour.nl/publication/2023-08-01-Solving-the-Identifying-Code-Set-Problem-with-Grouped-Independent-Support

Me, a young woman with long blonde hair wearing a pink blouse, standing in front of an academic poster, smilingly posing as if I am explaining it to someone. The poster is titled "Solving the Identifying Code Set Problem with Grouped Independent Support", and has a big pink block with white letters in the middle, which reads "by reducing to a computationally harder problem, we can exponentially decrease the encoding size, and solve much larger instances."

joshuagrochow, to ArtificialIntelligence
@joshuagrochow@mathstodon.xyz avatar

I love big-O notation when doing theory to focus on big ideas,

but constants can matter in practice, and often do!

(Leading constants moreso. To focus on leading constant but still ignore lower order terms you can use asymptotic equality ~)

(Inspired by @ccanonne on the birdiste.)

NicoleCRust, to Neuroscience
@NicoleCRust@neuromatch.social avatar

Looking for paper leads on: a genetic network w/ attractor states linked to brains

I'm fond of the approaches in this paper:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2571012/

The gist here is to model a genetic network as a dynamical system with two attractor states (in this case, it's leukemia and the states are apoptosis on-versus-off).

I'm looking for leads to papers that apply this type of approach to model genetic networks (not neural circuits) that have something a bit more to do with the brain; ideally not cancer.
(This is not my field). Huntington's? Fragile X? Anything neuron related?

Thanks in advance!

KeithDJohnson, to Futurology
@KeithDJohnson@sfba.social avatar

A selection of from my files. An asphalt drive and abandoned parking lot at a rest stop in W. Michigan, being reclaimed by Life.

I love it when that happens.
I like to help it along.
Resisting takes too much energy.

Further up the drive, wild grapes, creeping blackberries, and poison ivy grapple with grasses and forbs to colonize the asphalt.
Maples are totally colonizing the cracks in the cement curbs of the drive.

lukadotnet, to random Italian
@lukadotnet@mstdn.social avatar

Dopo un lungo lavoro da Agosto, ecco pubblicata la 1ma edizione del mio nuovo libro ❤️ 'Domina i problemi difficili abbracciando il Complexity-Thinking' 🎉 🥂 🎉 🥂 => https://leanpub.com/risolviproblemidifficiliabbracciandoilcomplexity-thinking/

Grazie alle prefazioni di Paolo Aversa e Marco Fainello e per le interviste e i consigli di praticanti illustri: Sunil Mundra, Daniel Mezick, Sonja Blignaut, Chris Matts, John Coleman, Valerie McLean, Tiani Jones, e Carol Mase.

NicoleCRust, to random
@NicoleCRust@neuromatch.social avatar

Word of the day: Stigmergy

https://en.wikipedia.org/wiki/Stigmergy

Stigmergy is a form of self-organization. It produces complex, seemingly intelligent structures, without need for any planning, control, or even direct communication between the agents. As such it supports efficient collaboration between extremely simple agents, who may lack memory or individual awareness of each other.

My new favorite paper on the topic:
https://doi.org/10.1073/pnas.1818759116

Describes how the characteristic shapes of the mounds of different species emerge. "During mound construction, environmental factors such as heat flow and gas exchange affect the building behavior of termites, and the resulting change in mound geometry in turn modifies the response of the internal mound environment to external thermal oscillations."

publicvoit, to microsoft
@publicvoit@graz.social avatar

@alex (this one: https://en.wikipedia.org/wiki/Alex_Stamos) on the latest Security Team hack allegedly by and Microsoft's public incident response including appropriate "translations" by Alex:

"Microsoft's Dangerous Addiction To Revenue" https://www.linkedin.com/pulse/microsofts-dangerous-addiction-security-revenue-alex-stamos-1ukzc

TL;DR: MS fucks up big time and is using that for selling more of their security services.

Background: https://www.wired.com/story/microsoft-hpe-midnight-blizzard-email-breaches/

mcpinson, to politics
@mcpinson@mas.to avatar

There's a reason that the can't manage its business:

blaise, to random
@blaise@hachyderm.io avatar

I like what @cvennevik says about tech debt
https://www.cvennevik.no/post/technical-debt-is-an-incomplete-model/
I have mentioned to @davefarley77 that the perspective on tech debt reflects an incomplete understanding of debt.
For example:
Secured vs unsecured
Simple vs compound interest
Fixed vs variable interest
Underlying vs derivative debt
Senior vs subordinate debt

Each of these reflect a decision with tradeoffs and benefits.

Has no one considered applying the kind of rigor we brought to, say, computational ?

manlius, to mastodon Italian
@manlius@mathstodon.xyz avatar

If you are curious about the novel results published in Science and Nature by the collaboration btw Meta and US academics, you might want to read

I try to build some background for non-experts of and summarize the main findings.

Finally, I dig into the ongoing debate, covering existing documents and my chats with Sandra González-Bailón, Sander van der Linden, Pierluigi Sacco and others

This debate might be of high interest for self-organized decentralized platforms, such as and the in general

You can read the (100% free) piece here: https://manlius.substack.com/p/are-social-media-undermining-democracy

If you find https://manlius.substack.com/ useful, please subscribe. It is (and will always be) free.

manlius, to Engineering Italian
@manlius@mathstodon.xyz avatar

A network that shaped our present: ~400,000 km of roads connecting thousands of cities & villages.

An emblematic physical manifestation of complex adaptive systems, allowing for goods, people and cultures to flow through continents and flourish along millennia.

amadeus, to random
@amadeus@mstdn.social avatar

I really don't understand why so many (s) limit the of (s). 🤔️

manlius, to science Italian
@manlius@mathstodon.xyz avatar

Following up a previous post about the topic, here there is the second (and maybe the last one) essay. What is the technological singularity and is this a real issue? Again, a perspective from , with a travel through , slime molds and black-hole computers.

Share your !

https://manlius.substack.com/p/from-science-fiction-to-science-facts

shekinahcancook, to Economics
@shekinahcancook@babka.social avatar

I think there are tons of people who would love a regular car, an EV or Hybrid, without all that other electronic junk. Purposefully making transitioning to cleaner options too expensive is a stupid policy.

toxi, (edited ) to generative
@toxi@mastodon.thi.ng avatar

Linear Memory (WIP), variations on a theme... exploring the terrain. Impressed by the resulting complexity, considering the simplicity of the system/setup...

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