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1. Changes of Magnetism in a Magnetic Insulator due to Proximity to a Topological Insulator

   https://doi.org/10.1103/PhysRevLett.125.017204  

   Liu, Tao; Kally, James; Pillsbury, Timothy; Liu, Chuanpu; Chang, Houchen; Ding, Jinjun; Cheng, Yang; Hilse, Maria; Engel-Herbert, Roman; Richardella, Anthony; et al (July 2020, Physical Review Letters)
2. Determination of a macro- to micro-scale progression leading to a magnetized plasma disruption

   https://doi.org/10.1063/1.5140348  

   Seo, Byonghoon; Wongwaitayakornkul, Pakorn; Haw, Magnus A.; Marshall, Ryan S.; Li, Hui; Bellan, Paul M. (February 2020, Physics of Plasmas)
3. To age or not to age: Anatomy of a supercooled liquid’s response to a high alternating electric field

   https://doi.org/10.1063/5.0138149  

   Richert, Ranko (January 2023, The Journal of Chemical Physics)

   Physical aging and structural recovery are the processes with which the structure of a system approaches equilibrium after some perturbation. Various methods exist, that initiate structural recovery, such as changing the temperature or applying a strong, external static field. This work is concerned with high alternating electric fields and their suitability to study structural recovery and aging. The present work demonstrates that rationalizing the nonlinear dielectric response of a supercooled liquid to high-amplitude ac-fields requires multiple fictive temperatures. This feature is in stark contrast to structural recovery after a temperature down-jump or a considerable increase in the static electric field, for which a single parameter, the fictive temperature or material time, describes the structural change. In other words, the structural recovery from a high ac-field does not adhere to time aging–time superposition, which is so characteristic of genuine aging processes. 

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4. Convergence to a diffusive contact wave for solutions to a system of hyperbolic balance laws

   https://doi.org/10.1142/S0219891623500078  

   Zeng, Yanni (March 2023, Journal of Hyperbolic Differential Equations)

   We consider a [Formula: see text] system of hyperbolic balance laws that is the converted form under inverse Hopf–Cole transformation of a Keller–Segel type chemotaxis model. We study Cauchy problem when Cauchy data connect two different end-states as [Formula: see text]. The background wave is a diffusive contact wave of the reduced system. We establish global existence of solution and study the time asymptotic behavior. In the special case where the cellular population initially approaches its stable equilibrium value as [Formula: see text], we obtain nonlinear stability of the diffusive contact wave under smallness assumption. In the general case where the population initially does not approach to its stable equilibrium value at least at one of the far fields, we use a correction function in the time asymptotic ansatz, and show that the population approaches logistically to its stable equilibrium value. Our result shows two significant differences when comparing to Euler equations with damping. The first one is the existence of a secondary wave in the time asymptotic ansatz. This implies that our solutions converge to the diffusive contact wave slower than those of Euler equations with damping. The second one is that the correction function logistically grows rather than exponentially decays. 

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5. Continuous Gesture Control of a Robot Arm: Performance Is Robust to a Variety of Hand-to-Robot Maps

   https://doi.org/10.1109/TBME.2023.3323601  

   Khan, Steafan E; Danziger, Zachary C (March 2024, IEEE Transactions on Biomedical Engineering)

   Objective: Despite advances in human-machine interface design, we lack the ability to give people precise and fast control over high degree of freedom (DOF) systems, like robotic limbs. Attempts to improve control often focus on the static map that links user input to device commands; hypothesizing that the user’s skill acquisition can be improved by finding an intuitive map. Here we investigate what map features affect skill acquisition. Methods: Each of our 36 participants used one of three maps that translated their 19-dimensional finger movement into the 5 robot joints and used the robot to pick up and move objects. The maps were each constructed to maximize a different control principle to reveal what features are most critical for user performance. 1) Principal Components Analysis to maximize the linear capture of finger variance, 2) our novel Egalitarian Principal Components Analysis to maximize the equality of variance captured by each component and 3) a Nonlinear Autoencoder to achieve both high variance capture and less biased variance allocation across latent dimensions Results: Despite large differences in the mapping structures there were no significant differences in group performance. Conclusion: Participants’ natural aptitude had a far greater effect on performance than the map. Significance: Robot-user interfaces are becoming increasingly common and require new designs to make them easier to operate. Here we show that optimizing the map may not be the appropriate target to improve operator skill. Therefore, further efforts should focus on other aspects of the robot-user-interface such as feedback or learning environment. 

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