Results 91 to 100 of about 30,092 (257)

Extensions of Stein's Lemma for the Skew-Normal Distribution [PDF]

open access: yesCommunications in Statistics - Theory and Methods, 2007
When two random variables have a bivariate normal distribution, Stein's lemma (Stein, 1973, 1981), provides, under certain regularity conditions, an expression for the covariance of the first variable with a function of the second. An extension of the lemma due to Liu (1994) as well as to Stein himself establishes an analogous result for a vector of ...
openaire   +2 more sources

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

open access: yesAdvanced 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   +2 more
wiley   +1 more source

Classification Methods for the Serological Status Based on Mixtures of Skew-Normal and Skew-t Distributions

open access: yesMathematics
Gaussian mixture models are widely employed in serological data analysis to discern between seropositive and seronegative individuals. However, serological populations often exhibit significant skewness, making symmetric distributions like Normal or ...
Tiago Dias-Domingues   +2 more
doaj   +1 more source

Modeling asymmetric compositional data

open access: yesActa Scientiarum: Technology, 2014
Compositional data belong to the simplex sample space, but they are transformed to the sample space of the real numbers using the additive log-ratio transformation to allow the application of standard statistical techniques.
Ana Beatriz Tozzo Martins   +4 more
doaj   +1 more source

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

open access: yesAdvanced 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   +3 more
wiley   +1 more source

Efficient and Robust Standing Postures of Quadruped Robots

open access: yesAdvanced 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   +5 more
wiley   +1 more source

Applications of Skew Models Using Generalized Logistic Distribution

open access: yesAxioms, 2016
We use the skew distribution generation procedure proposed by Azzalini [Scand. J. Stat., 1985, 12, 171–178] to create three new probability distribution functions.
Pushpa Narayan Rathie   +2 more
doaj   +1 more source

In Situ X‐Ray Tomography and Acoustic Emission Monitoring of Damage Evolution in C/C‐SiC Composites Fabricated by Liquid Silicon Infiltration

open access: yesAdvanced Science, EarlyView.
This study investigates how the internal structure of fiber‐reinforced ceramic composites affects their resistance to damage. By combining 3D X‐ray imaging with acoustic emission monitoring during mechanical testing, it reveals how silicon distribution influences crack formation.
Yang Chen   +7 more
wiley   +1 more source

RNA Helicase DDX21 Controls CD4+ T Cell Proliferation and Promotes Inflammatory Bowel Disease via Translational Control

open access: yesAdvanced Science, EarlyView.
ABSTRACT Inflammatory bowel disease (IBD) is characterized by dysregulated T cell responses. RNA helicases, including DExD‐box helicase 21 (DDX21), are pivotal in RNA metabolism, but their role in T cell‐mediated pathology during IBD remains unclear. Here, we demonstrate that DDX21 expression in CD4+ T cells correlates with cell cycle and translation ...
Yujuan Zhang   +11 more
wiley   +1 more source

Adult Sex Ratio as a Demographic Feedback Linking Mating Systems, Parental Care, and Evolution

open access: yesAdvanced Science, EarlyView.
Breeding systems are some of the most diverse social behavior, and our team is investigation the evolutionary causes of this diversity. This review summarises our research carried out at the University of Bath. We argue that demographic components of wild populations, especially the adult sex ratio, plays a key role driving breeding system variation ...
Tamás Székely, Oscar G. Miranda
wiley   +1 more source

Home - About - Disclaimer - Privacy