Severe vibration may occur in structures such as high-rise buildings and bridges according to wind seismic excitations, large space due their lightweight flexible constitution. Generally, when several modes are simultaneously excited, application of the model-based control strategies become difficult. In this study, we propose a wave absorption method for reducing vibrations multi-degree-of-fre...

This paper presents a compact metal plate lens antenna for evaluating a wave absorber placed on ceiling of the ETC gate. The focal distance of the lens was derived to be 129 cm by the geometrical optics procedure. By arranging the lens in front of a horn antenna, the gain and beamwidth characteristics were improved from 18 dBi to 26 dBi and from 22 degrees to 7 degrees, respectively. Then the a...

1. Absorption of waves means generation of waves. A body oscillating in water will produce waves. A big body and a small body may produce equally large waves provided the smaller body oscillates with larger amplitude. This may be utilised for the purpose of wave energy conversion, for instance by a small floating body heaving in response to an incident wave, in particular so if it can be arrang...

The interaction between trace shortwave radiative absorbers and the dynamical circulation is shown to be linearly unstable for horizontally uniform basic states with a vertical gradient in the basic state absorber mixing ratio. Two types of instability are identified, described as the advective mode and the propagating mode. The advective mode is usually unstable when the basic state absorber m...