'Swarmalators' better envision synchronized microbots
Mar 2023, phys.org
The researchers simplified their model to work with just four mathematical constants linked together to produce diverse emergent behaviors, such as aggregation, dispersion, vortices, traveling waves, and bouncing clusters.
The new model can mimic particles in nature that each operate at different natural frequencies, as some objects move slower and faster around a trajectory than others. The researchers also added chirality, or the ability for a particle to move in a circle, because many examples in nature, such as sperm, swim in circles and in vortices. And particles in the model exhibit local coupling, so they sense and respond only to their local neighbors.
At its core, the model combines swarming behaviors with synchronization in time.
"Swarmalators"
via Cornell University: Steven Ceron et al, Diverse behaviors in non-uniform chiral and non-chiral swarmalators, Nature Communications (2023). DOI: 10.1038/s41467-023-36563-4
Drones navigate unseen environments with liquid neural networks
Apr 2023, phys.org
First, a retronym in the making:
"Inspired by the adaptable nature of organic brains, researchers have introduced..."
You start referring to regular human brains as "organic brains" once some other kind of brain becomes important enough to force a distinction.
The liquid neural networks can continuously adapt to new data inputs to make reliable decisions in unknown domains like forests, urban landscapes, and environments with added noise, rotation, and occlusion.
The new class of machine-learning algorithms captures the causal structure of tasks from high-dimensional, unstructured data, such as pixel inputs from a drone-mounted camera to extract crucial aspects of a task and ignore irrelevant features.
"Our experiments demonstrate that we can effectively teach a drone to locate an object in a forest during summer, and then deploy the model in winter, with vastly different surroundings. These flexible algorithms could one day aid in decision-making based on data streams that change over time, such as medical diagnosis and autonomous driving applications."
Unlike traditional neural networks that only learn during the training phase, the liquid neural net's parameters can change over time, making them not only interpretable, but more resilient to unexpected or noisy data.
Note, these are not the liquid neural networks described by others, where the "liquid" part of the analogy, or neologism, is literally a fluid that transports neurotransmitters, like hormones in the bloodstream or even antibodies in the immune system, and this differs from the idea of a neural network as one made of electric circuits.
via MIT's Computer Science and Artificial Intelligence Laboratory: Makram Chahine et al, Robust flight navigation out of distribution with liquid neural networks, Science Robotics (2023). DOI: 10.1126/scirobotics.adc8892
In sync brainwaves predict learning, study shows
Apr 2023, phys.org
Students whose brainwaves are more in sync with their classmates and teacher are likely to learn better than those lacking this "brain-to-brain synchrony"
The researchers found that as students were listening to the lecture, their brainwaves became in sync with one another. Moreover, the researchers observed such "brain-to-brain synchrony"—similar brain-activity patterns over time—between the students' brainwaves and when comparing students' brainwaves to the teacher's brainwaves.
via NYU: The Temporal Dynamics of Brain-to-Brain Synchrony Between Students and Teachers Predict Learning Outcomes, Psychological Science (2023). DOI: 10.1177/09567976231163872
Post Script: If you look at the thumbnail for this story, it shows a woman wearing what looks like the Emotiv EEG headset. I bought one of those ten years ago for my high school students to try out, so they could experience playing video games with their minds. Immediately I realized that my students with tight curls (like "black people hair" vs "white people hair") definitely did not get the same connection -- the headset reads brainwaves via electrical currents, and if the headset can't make contact with the scalp, it can't read the electricity. That pissed me off and I stopped using it. Maybe they fixed that problem since ten years ago; maybe they didn't. That's what makes me wonder how science can perpetuate systemic racism, even though science is supposed to be blind to these things. In fact, some might say that the sole purpose of the scientific method is to reduce the bias of your investigation to the smallest amount possible, thus revealing as much of the truth as possible.
Swarming microrobots self-organize into diverse patterns
Jun 2023, phys.org
The microrobots in this case are 3D-printed polymer discs, each roughly the width of a human hair, that have been sputter-coated with a thin layer of a ferromagnetic material and set in a 1.5-centimeter-wide pool of water.
The researchers applied two orthogonal external oscillating magnetic fields and adjusted their amplitude and frequency, causing each microrobot to spin on its center axis and generate its own flows. This movement in turn produced a series of magnetic, hydrodynamic and capillary forces.
"By changing the global magnetic field, we can change the relative magnitudes of those forces, " Petersen said. "And that changes the overall behavior of the swarm."
But wait -- "The reason why we're always excited when the systems are capable of caging and expulsion is that you could, for example, drink a vial with little microrobots that are completely inert to your human body, have them cage and transport medicine, and then bring it to the right point in your body and release it," Petersen said. "It's not perfect manipulation of objects, but in the behaviors of these microscale systems we're starting to see a lot of parallels to more sophisticated robots despite their lack of computation, which is pretty exciting."
(Yes, drinking a glass of microbot swarms does sound like the ideal method of drug delivery, yes it does.)
Also, just a reminder: The Swarmalator is swarming oscillator model
via Cornell and Max Planck Institute for Intelligent Systems: Steven Ceron et al, Programmable self-organization of heterogeneous microrobot collectives, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2221913120
COVID lockdown - Are high-income earners more resistant to returning to the office?
Aug 2023, phys.org
I'm just here because this is the first paper published by Northeastern's Network Science Institute program in London: Northeastern expanded its world leading Network Science Institute to the university's campus in London this summer (2023) in a move to establish a new European hub in the fast-growing research field of network science.
But I stayed for the word synchronicity: High-income workers have the leverage to negotiate more for remote work, Di Clemente says. "They are the ones that can actually change their synchronicity," he says, adding that part of that workforce "might never come back" to physical offices full time.
via Northeastern University: Clodomir Santana et al, COVID-19 is linked to changes in the time–space dimension of human mobility, Nature Human Behaviour (2023). DOI: 10.1038/s41562-023-01660-3
A system to keep cloud-based gamers in sync
Aug 2023, phys.org
Listen up, writers of interplanetary science fiction:
Their system, called Ekho, adds inaudible white noise sequences to the game audio streamed from the cloud server. Then it listens for those sequences in the audio recorded by the player's controller.
Ekho uses the mismatch between these noise sequences to continuously measure and compensate for the interstream delay.
via MIT and Microsoft: Ekho: Synchronizing Cloud Gaming Media Across Multiple Endpoints. Pouya Hamadanian, D Gallatin, M Alizadeh, K Chintalapudi
 |
Image credit: TPUv3 Pod - Google Labs - 2018 |
Making sense of life's random rhythms: Team suggests universal framework for understanding 'oscillations'
Aug 2023, phys.org
Studying stochastic, random oscillations like the synchronized blinking of fireflies, the back-and-forth motion of a child's swing, slight variations in the the human heartbeat. "If your heart cells aren't synchronized, you die of atrial fibrillation," Thomas said. "But if your brain cells synchronize too much, you have Parkinson's disease, or epilepsy,
"We turned the problem of comparing oscillators into a linear algebra problem"
Most oscillations are irregular; a natural variation of 5-10% in the heartbeat is considered healthy. "In San Francisco, modern skyscrapers sway in the wind, buffeted by randomly shifting air currents—they're pushed slightly out of their vertical posture, but the mechanical properties of the structure pull them back. This combination of flexibility and resilience helps high-rise buildings survive shaking during earthquakes. You wouldn't think this process could be compared with brain waves, but our new formalism lets you compare them."
via Case Western: Alberto Pérez-Cervera et al, A universal description of stochastic oscillators, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2303222120
Fireflies, brain cells, dancers: Synchronization research shows nature's perfect timing is all about connections
Sep 2023, phys.org
They figured out a way to predict the synchronization between coupled oscillators by the network structure that connects them, and have revealed the impact of patterns of network connections among small groups of nodes (motifs) on the whole of network synchronizability. Results implicate the prevalence of clustered structure such as feedforward and feedback loops as the most important factor in synchronizability.
"Clustered structure"
"We present an analytic technique to directly measure the relative synchronizability of noise-driven time-series processes on networks, in terms of the directed network structure, and reveal subtle differences between the motifs involved for discrete or continuous-time dynamics.
via University of Sydney and Max Planck Institute for Mathematics in the Sciences in Leipzig: Joseph T. Lizier et al, Analytic relationship of relative synchronizability to network structure and motifs, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2303332120
Adaptive optical neural network connects thousands of artificial neurons
Oct 2023, phys.org
A network consisting of almost 8,400 optical neurons made of waveguide-coupled phase-change material; the connection between two each of these neurons can indeed become stronger or weaker (synaptic plasticity), and that new connections can be formed, or existing ones eliminated (structural plasticity).
These synapses were not hardware elements but were coded as a result of the properties of the optical pulses -- in other words, as a result of the respective wavelength and of the intensity of the optical pulse. This made it possible to integrate several thousand neurons on one single chip and connect them optically.
(btw) The researchers tested the performance of the neural network by using an evolutionary algorithm to train it to distinguish between German and English texts. The recognition parameter they used was the number of vowels in the text.
via Collaborative Research Center 1459 (Intelligent Matter) at University of Münster and Universities of Exeter and Oxford: Frank Brückerhoff-Plückelmann et al, Event-driven adaptive optical neural network, Science Advances (2023). DOI: 10.1126/sciadv.adi9127
