Results 111 to 120 of about 251,804 (253)

Measurements of the Low-acceleration Gravitational Anomaly from the Normalized Velocity Profile of Gaia Wide Binary Stars and Statistical Testing of Newtonian and Milgromian Theories

The Astrophysical Journal
Low-acceleration gravitational anomaly is investigated with a new method of exploiting the normalized velocity profile $\tilde{v}\equiv {v}_{p}/{v}_{c}$ of wide binary stars as a function of the normalized sky-projected radius s / r _M , where v _p is ...
Kyu-Hyun Chae
doaj   +1 more source

Hard‐Magnetic Soft Millirobots in Underactuated Systems

Advanced Robotics Research, EarlyView.
This review provides a comprehensive overview of hard‐magnetic soft millirobots in underactuated systems. It examines key advances in structural design, physics‐informed modeling, and control strategies, while highlighting the interplay among these domains.
Qiong Wang, Zixuan Zhang, Bingyan Li, Junkai Wang, Hongcheng Gu   +4 more
wiley   +1 more source

Bayesian Inference of Gravity through Realistic 3D Modeling of Wide Binary Orbits: General Algorithm and a Pilot Study with HARPS Radial Velocities

The Astrophysical Journal Letters
When 3D relative displacement r and velocity v between the pair in a gravitationally bound system are precisely measured, the six measured quantities at one phase can allow elliptical orbit solutions at a given gravitational parameter G .
Kyu-Hyun Chae
doaj   +1 more source

Identifying Physical Interactions in Contact‐Based Robot Manipulation for Learning from Demonstration

Advanced Robotics Research, EarlyView.
Robots can learn manipulation tasks from human demonstrations. This work proposes a versatile method to identify the physical interactions that occur in a demonstration, such as sequences of different contacts and interactions with mechanical constraints.
Alex Harm Gert‐Jan Overbeek, Herman van der Kooij, Douwe Dresscher, Mark Vlutters   +3 more
wiley   +1 more source

Photon Rings and Shadow Size for General Axisymmetric and Stationary Integrable Spacetimes

The Astrophysical Journal
There are now multiple direct probes of the region near black hole horizons, including direct imaging with the Event Horizon Telescope (EHT). As a result, it is now of considerable interest to identify what aspects of the underlying spacetime are ...
Kiana Salehi, Avery E. Broderick, Boris Georgiev   +2 more
doaj   +1 more source

Squaring the Magic

, 2012
We construct and classify all possible Magic Squares (MS's) related to Euclidean or Lorentzian rank-3 simple Jordan algebras, both on normed division algebras and split composition algebras.
Cacciatori, Sergio L., Cerchiai, Bianca L., Marrani, Alessio   +2 more
core  

Asymmetry in Skipping Enhances Viability Against Control Input Noise

Advanced Robotics Research, EarlyView.
Quadruped animals use asymmetric galloping gaits at high speeds, yet the functional role of this asymmetry remains unclear. This study shows that left–right asymmetry in touchdown angles enhances robustness to control noise. Using a simple two‐legged locomotion model and viability theory, it demonstrates that asymmetric skipping substantially enlarges ...
Yuichi Ambe, Alvin So, Shinya Aoi
wiley   +1 more source

Probing the Nature of Gravity in the Low-acceleration Limit: Wide Binaries of Extreme Separations with Perspective Effects

The Astrophysical Journal
Recent statistical analyses of wide binaries have revealed a boost in gravitational acceleration with respect to the prediction by Newtonian gravity at low internal accelerations ≲10 ^−9 m s ^−2 .
Youngsub Yoon, Yong Tian, Kyu-Hyun Chae
doaj   +1 more source

Continuum Mechanics Modeling of Flexible Spring Joints in Surgical Robots

Advanced Robotics Research, EarlyView.
A new mechanical model of a tendon‐actuated helical extension spring joint in surgical robots is built using Cosserat rod theory. The model can implicitly handle the unknown contacts between adjacent coils and numerically predict spring shapes from straight to significantly bent under actuation forces.
Botian Sun, Liang Zhang, Jianwen Zeng, Xuefeng Wang   +3 more
wiley   +1 more source

Low-acceleration Gravitational Anomaly from Bayesian 3D Modeling of Wide Binary Orbits: Methodology and Results with Gaia Data Release 3

The Astrophysical Journal
Isolated wide binary stars provide natural laboratories to directly probe gravity for Newtonian acceleration of g _N  ≲ 10 ^−9 m s ^−2 . Recent statistical analyses of wide binaries have been performed only with sky-projected relative velocities v _p in ...
Kyu-Hyun Chae
doaj   +1 more source