Results 21 to 30 of about 279,578 (265)

Critical Steady-State Response of Single-Degree-of-Freedom Bilinear Hysteretic System under Multi Impulse as Substitute of Long-Duration Ground Motion

Frontiers in Built Environment, 2017
A set of multiple impulses is introduced as a substitute of many-cycle harmonic waves which represent the long-duration earthquake ground motion. A closed-form expression is derived of the elastic–plastic response of a single-degree-of-freedom structure ...
Kotaro Kojima, Izuru Takewaki
doaj   +1 more source

Optimal Viscous Damper Placement for Elastic-Plastic MDOF Structures Under Critical Double Impulse

Frontiers in Built Environment, 2019
A new method for optimal viscous damper placement is proposed for elastic-plastic multi-degree-of-freedom (MDOF) structures subjected to the critical double impulse as a representative of near-fault ground motions.
Hiroki Akehashi, Izuru Takewaki
doaj   +1 more source

Critical Earthquake Response of 2DOF Elastic-Perfectly Plastic Model Under Multiple Impulse as Substitute for Long-Duration Earthquake Ground Motions

Frontiers in Built Environment, 2019
An equi-spaced consecutive impulse input is treated as a simplified representative for a long-duration earthquake ground motion. The key property of such input can be captured approximately by using harmonic waves.
Yoshito Saotome, Kotaro Kojima, Izuru Takewaki   +2 more
doaj   +1 more source

Analysis of Synchronous Generator Self-Excitation under Capacitive Load Condition in Variable-Frequency Aviation Power System

Machines, 2022
As power electronic converters become more widely used in aviation power systems, the associated capacitive loads in the harmonic filter circuits increase accordingly.
Haigang Liu, Chu Sun, Mengyu He, Na Wang, Yuanjun Zhou   +4 more
doaj   +1 more source

High pressure effects on the excitation spectra and dipole properties of Li, Be+, and B2+ atoms under confinement

Matter and Radiation at Extremes, 2020
Properties of atoms and molecules undergo significant changes when subjected to spatial confinement. We study the excitation spectra of lithium-like atoms in the initial 1s22s electronic configuration when confined by an impenetrable spherical cavity. We
C. Martínez-Flores, R. Cabrera-Trujillo
doaj   +1 more source

Critical properties of quantum three- and four-state Potts models with boundaries polarized along the transverse field

SciPost Physics Core, 2022
By computing the low-lying energy excitation spectra with the density matrix renormalization group algorithm we show that boundaries polarized in the direction of the transverse field lead to scale-invariant conformal towers of states at the critical ...
Natalia Chepiga
doaj   +1 more source

Velocity of excitations in ordered, disordered, and critical antiferromagnets

Physical Review B, 2015
We test three different approaches, based on quantum Monte Carlo simulations, for computing the velocity $c$ of triplet excitations in antiferromagnets. We consider the standard $S=1/2$ one- and two-dimensional Heisenberg models, as well as a bilayer Heisenberg model at its critical point.
Sen, Arnab, Suwa, Hidemaro, Sandvik, Anders W.   +2 more
openaire   +3 more sources

Safe Model-Based Reinforcement Learning for Systems With Parametric Uncertainties

Frontiers in Robotics and AI, 2021
Reinforcement learning has been established over the past decade as an effective tool to find optimal control policies for dynamical systems, with recent focus on approaches that guarantee safety during the learning and/or execution phases.
S. M. Nahid Mahmud, Scott A. Nivison, Zachary I. Bell, Rushikesh Kamalapurkar   +3 more
doaj   +1 more source

Nonstationary Random Critical Seismic Excitations [PDF]

Journal of Engineering Mechanics, 1987
A method is presented to find nonstationary random seismic excitations with a constraint on mean square value such that the response variance of a given linear system is maximized. It is also possible to incorporate the dominant input frequency into the analysis.
Iyengar, RN, Manohar, CS
openaire   +1 more source

Surrogate impulse ground motion for practical simulation of critical nonlinear structural responses

Frontiers in Built Environment
Impulse-based representations of earthquake ground motions provide an efficient framework for evaluating critical nonlinear structural responses. However, the direct use of ideal impulse ground motions expressed by Dirac’s delta function may excite all ...
Hiroki Akehashi, Mao Kinoshita, Fumiya Ueno, Koji Yamato, Yusuke Ehara, Tatsuhiko Maeda   +5 more
doaj   +1 more source