Publications related to Polar coordinate system

'Fraternal-twin' ferroelectricity: competing polar states in hydrogen-doped samarium nickelate from first principles

In ferroelectric switching, an applied electric field switches the system between two polar symmetry-equivalent states. In this work, we use first-principles calculations to explore the polar states of hydrogen-doped samarium nickelate (SNO) at a concentra ...

Iop Publishing Ltd2024

A geometric optimal control approach for imitation and generalization of manipulation skills

Sylvain Calinon, Amirreza Razmjoo Fard, Jie Zhao

Daily manipulation tasks are characterized by regular features associated with the task structure, which can be described by multiple geometric primitives related to actions and object shapes. Only using Cartesian coordinate systems cannot fully represent ...

Elsevier2023

Learning Linearized Degradation of Health Indicators using Deep Koopman Operator Approach

Olga Fink, Sergei Garmaev

With the current trend of increasing complexity of industrial systems, the construction and monitoring of health indicators becomes even more challenging. Given that health indicators are commonly employed to predict the end of life, a crucial criterion fo ...

Research Publishing2023

Asymmetric phase modulation of light with parity-symmetry broken metasurfaces

Karim Achouri, Jean-Yves Duboz

The design of wavefront-shaping devices is conventionally approached using real-frequency modeling. However, since these devices interact with light through radiative channels, they are by default non-Hermitian objects having complex eigenvalues (poles and ...

Optica Publishing Group2023

Gait Phase Estimation in Steady Walking: A Comparative Study of Methods Based on the Phase Portrait of the Hip Angle

Auke Ijspeert, Mohamed Bouri, Ali Reza Manzoori, Coline Lugaz, Tian Ye, Davide Malatesta

Accurate real-time estimation of the gait phase (GP) is crucial for many control methods in exoskeletons and prostheses. A class of approaches to GP estimation construct the phase portrait of a segment or joint angle, and use the normalized polar angle of ...

IEEE Xplore2023

Enhancement of brain atlases with region-specific coordinate systems: flatmaps and barrel column annotations

Michael Reimann, Armando Romani, Aleksandra Zuzanna Teska, Felix Schürmann, Juan Bautista Hernando Vieites, Huanxiang Lu, Sirio Bolaños Puchet

Digital brain atlases define a hierarchy of brain regions and their locations in three-dimensional space. They provide a standard coordinate system in which diverse datasets can be integrated for visualization and analysis. They also enable building of dat ...

2024

The elliptical Ornstein-Uhlenbeck process

Sofia Charlotta Olhede

We introduce the elliptical Ornstein-Uhlenbeck (OU) process, which is a generalisation of the well-known univariate OU process to bivariate time series. This process maps out elliptical stochastic oscillations over time in the complex plane, which are obse ...

INT PRESS BOSTON, INC2023

Principle and Analysis of Radial-Force-Based Swirling Actuator for Low-Speed High-Torque Applications

Adrien Jean-Michel Thabuis

This article proposes a swirling actuator that uses the electromagnetic radial force and mechanical gears to generate rotational torque. The proposed actuator generates a rotating radial force between an inner stator and a swirler. The gears on the swirler ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Clustering and Informative Path Planning for 3D Gas Distribution Mapping: Algorithms and Performance Evaluation

Alcherio Martinoli, Chiara Ercolani, Lixuan Tang, Ankita Arun Humne

Chemical gas dispersion can represent a severe threat to human and animal lives, as well as to the environment. Constructing a map of the distribution of gas in a fast and reliable manner is critical to ensure accurate monitoring of at-risk facilities and ...

2022

Structures of SAS-6 coiled coil hold implications for the polarity of the centriolar cartwheel

Pierre Gönczy, Georgios Hatzopoulos

Centrioles are eukaryotic organelles that template the formation of cilia and flagella, as well as organize the microtubule network and the mitotic spindle in animal cells. Centrioles have proximal-distal polarity and a 9 fold radial symmetry imparted by a ...

CELL PRESS2022

Compound Admittance Matrix Estimation of Three-phase Untransposed Power Distribution Grids using Synchrophasor Measurements

Jean-Yves Le Boudec, Mario Paolone, Fabrizio Sossan, Rahul Kumar Gupta

The paper considers the problem of estimating the parameters of the compound admittance matrix of three-phase untransposed low-and medium-voltage electrical distribution networks using synchrophasor measurements from phasor measurement units (PMUs). The wo ...

2021

Charge-based modeling of ultra narrow junctionless cylindrical nanowire FETs

Farzan Jazaeri

This brief proposes an analytical approach to model the DC electrical behavior of extremely narrow cylindrical junctionless nanowire field-effect transistors (JL-NW-FETs). The model includes explicit expressions, taking into account the first-order perturb ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Free Boundary Regularity for Almost Every Solution to the Signorini Problem

Xavier Fernandez-Real Girona

We investigate the regularity of the free boundary for the Signorini problem in Rn+1. It is known that regular points are (n−1)-dimensional and C∞. However, even for C∞ obstacles φ, the set of non-regular (or degenerate) points could be very large—e.g. wit ...

2021

A stability theory beyond the co-rotational setting for critical wave maps blow up

Joachim Krieger, Shuang Miao

We exhibit non-equivariant perturbations of the blowup solutions constructed in [18] for energy critical wave maps into

\mathbb{S}^2

. Our admissible class of perturbations is an open set in some sufficiently smooth topology and vanishes near the light co ...

2020

On benchmarking of simulations of particle transport in ITER

Olivier Sauter, Francesca Maria Poli, Federico Alberto Alfredo Felici, Javier García Hernández, Anna Teplukhina, Xiao Yuan

We report results of benchmarking of core particle transport simulations by a collection of codes widely used in transport modelling of tokamak plasmas. Our analysis includes formulation of transport equations, difference between electron and ion solvers, ...

IOP Publishing Ltd2019

Radial coordinates for defect CFTs

Marco Meineri

We study the two-point function of local operators in the presence of a defect in a generic conformal field theory. We define two pairs of cross ratios, which are convenient in the analysis of the OPE in the bulk and defect channel respectively. The new co ...

Springer Nature2018

Learning Proximal Operators with Gaussian Processes

Colin Neil Jones, Georgios Stathopoulos, Xuan Truong Nghiem

Several distributed-optimization setups involve a group of agents coordinated by a central entity (coordinator), altogether operating in a collaborative framework. In such environments, it is often common that the agents solve proximal minimization problem ...

IEEE2018

Geometric Optimization of a Reciprocal Floor-Framing System with Self-Weight and Area-Loading Considerations

Corentin Jean Dominique Fivet

This paper explores the geometric optimization of a planar reciprocal frame (RF) floor framing structure, focusing on the triangular topology. The structural performance of the frames is computed and plotted against the geometric parameters for various loa ...

2017

Microbranching instability in phase-field modelling of dynamic brittle fracture

Jean-François Molinari, Jérémy Bleyer

The microbranching instability occurring for rapidly propagating cracks in brittle materials has been described in various experiments as an intrinsically three-dimensional phenomenon. Using a variational phase-field model, we show that the microbranching ...

AIP American Institute of Physics2017

Synthesis, structural elucidation and biological activities of organotin(IV) derivatives of 4-(2-thienyl)butyric acid

Paul Joseph Dyson

A series of tri- and diorganotin(IV) derivatives of 4-(2-thienyl)butyric acid have been synthesized by the reaction of ligand acid with tri- and diorganotin salts in 1:1 and 2:1 molar ratios, respectively. The synthesized compounds have been confirmed by C ...

Springer2017