During the 2011 Tohoku Earthquake, gymnasium buildings sustained unexpected structural damage, preventing their use as evacuation shelters. This study examines one such severely damaged structure with fewer connections between steel roof and reinforced concrete columns. Results of eigenvalue, pushover, seismic response analyses elucidate observed damage. The out-of-plane deformation is prominen...

This paper presents a recursive method of modal parameters identification based on operational measurements, dedicated for non-stationary systems. Decoupling signal components procedure allowed to reduce the signal model and simplified the process of modal parameters estimation. Adaptive method of filtering simplified the process of wavelet function selection. Presented method utilize Continuou...

This paper addresses the problem of reducing the effects of wavefront distortions in ground-based telescopes within a "Modal-Control" framework. The proposed approach allows the designer to optimize the Youla parameter of a given modal controller with respect to a relevant adaptive optics performance criterion defined on a "sampled" frequency domain. This feature makes it possible to use turbul...

A nearfield broadband adaptive beamforming approach based on the modal expansion of the solution to the spherical wave equation is formulated. It provides an efficient parameterization for the nearfield beamforming problem with a single parameter to focus the beamformer to a desired operating radius and a set of modal coefficients to control the angular response. As a consequence, the adaptive ...

Split-hom together structure is a new heavy load rack structure, and its reliability needs to be verified. Through analyzing multimodal hom-connection principle from the perspective of bionics and contact mechanics, the article puts forward three kinds of hom-connection methods and establishes the finite element model and mathematical model of the rack. Afterwards, the finite element model and ...

Reduced-Order Reference Models for Adaptive Control of Space Structures Alexander I. Scherling In addition to serving as a brief overview of aspects relevant to reducedorder modeling (in particular balanced-state and modal techniques) as applied to structural finite element models, this work produced tools for visualizing the relationship between the modes of a model and the states of its balan...

We present a prototype of an adaptive intraocular lens based on a modal liquid-crystal spatial phase modulator with wireless control. The modal corrector consists of a nematic liquid-crystal layer sandwiched between two glass substrates with transparent low- and high-ohmic electrodes, respectively. Adaptive correction of ocular aberrations is achieved by changing the amplitude and the frequency...