Results 121 to 130 of about 17,511,424 (267)

Portfolio optimization for student t and skewed t returns

It is well-established that equity returns are not Normally distributed, but what should the portfolio manager do about this, and is it worth the effort?
Wenbo Hu, Alec Kercheval
core   +1 more source

Programmable Variable‐Stiffness Multilayer Elastomer Composites With High‐Aspect‐Ratio Low‐Melting‐Point Alloy Inclusions

Advanced Materials Technologies, EarlyView.
High‐aspect‐ratio low‐melting‐point alloy inclusions are embedded within multilayer silicone laminates to create thermally programmable stiffness. Sequential activation of alloy‐rich layers produces four distinct mechanical states and reconfigures tendon‐driven actuator trajectories under the same load.
Palpolage Don Shehan Hiroshan Gunawardane, Gyan Edbert Zesiro, Hao Zhou, Gursel Alici, Mu Chiao   +4 more
wiley   +1 more source

Photoluminescence Reshaping via Structural Confinement and Local Density of Optical States Control in Ir(III)‐Doped Biodegradable Metasurfaces

Advanced Materials Technologies, EarlyView.
Phosphorescent biodegradable metasurface showing vibronic selection and spectral photoluminescence narrowing. Anti‐correlation between experimental LDOS and measured lifetimes. ABSTRACT Metasurfaces incorporating phosphorescent emitters offer a route to engineer radiative and vibronic processes beyond chemical design.
Vincenzo Caligiuri, Andrea Smeriglio, Svetlana Siprova, Olga Favale, Francesca Leone, Roberto Termine, Debora Policastro, Alessandra Crispini, Attilio Golemme, Nicolas Godbert, Iolinda Aiello, Antonio De Luca   +11 more
wiley   +1 more source

Geometry‐Driven Whispering‐Gallery Modes in Self‐Assembled Phosphorescent Organic Microtubes

Advanced Optical Materials, EarlyView.
Micelles encapsulating tris(2‐phenylpyridine)iridium(III) self‐assemble into a hollow hexagonal microtube stabilized by a surface passivation layer. The hexagonal cross‐section confines circulating light along its facets, sustaining sharp whispering‐gallery resonances that guide photoluminescence emission under laser excitation.
Do Wan Kim, Seokho Kim, Jinho Choi, Sang‐hun Lee, Seongwan Bae, Jongho Kim, Sangjun Lee, Junseok Heo, Sangin Kim, Kyusang Lee, Dong Hyuk Park   +10 more
wiley   +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

A State‐Adaptive Koopman Control Framework for Real‐Time Deformable Tool Manipulation in Robotic Environmental Swabbing

Advanced Robotics Research, EarlyView.
This work presents a state‐adaptive Koopman linear quadratic regulator framework for real‐time manipulation of a deformable swab tool in robotic environmental sampling. By combining Koopman linearization, tactile sensing, and centroid‐based force regulation, the system maintains stable contact forces and high coverage across flat and inclined surfaces.
Siavash Mahmoudi, Amirreza Davar, Dongyi Wang   +2 more
wiley   +1 more source

Compliant Pneumatic Feet with Real‐Time Stiffness Adaptation for Humanoid Locomotion

Advanced Robotics Research, EarlyView.
A compliant pneumatic foot with real‐time variable stiffness enables humanoid robots to adapt to changing terrains. Using onboard vision and pressure control, the foot modulates stiffness within each gait cycle, reducing impact forces and improving balance. The design, cast in soft silicone with embedded air chambers and Kevlar wrapping, offers durable,
Irene Frizza, Hiroshi Kaminaga, Philippe Fraisse, Gentiane Venture   +3 more
wiley   +1 more source

From Skews to a Skewed-t [PDF]

In this paper we present a new methodology to infer the implied risk-neutral distribution function from European-style options. We introduce a skewed version of the Student-t distribution, whose main advantage is that its shape depends on only four ...
Jong, C.M. de, Huisman, R.
core  

Efficient and Robust Standing Postures of Quadruped Robots

Advanced Robotics Research, EarlyView.
A calibrated static framework estimates load, optimizes torques, and adapts posture so quadruped robots stand efficiently and robustly under external payloads, achieving up to 50% lower torque demand. Inspired by the natural posture adjustments of animals under external loading, this article presents an optimization‐based framework for minimizing joint
Mohamad Kanaan, Hamza Jomaa, Jack Challita, Kawthar Zaidan, Riad Saab, Hussein Hussein   +5 more
wiley   +1 more source

Multivariate Student -t Regression Models: Pitfalls and Inference [PDF]

We consider likelihood-based inference from multivariate regression models with independent Student-t errors. Some very intruiging pitfalls of both Bayesian and classical methods on the basis of point observations are uncovered. Bayesian inference may be
Steel, M.F.J., Fernández, C.
core