Narrow Terrain Research Articles

2A1-S-018 狭隘不整地対応型3輪ロボットの開発(車輪移動ロボット3,生活を支援するロボメカ技術のメガインテグレーション)

2A1-S-018 狭隘不整地対応型3輪ロボットの開発(車輪移動ロボット3,生活を支援するロボメカ技術のメガインテグレーション)

Low-frequency ground wave propagation over narrow terrain features

Solutions of the one- and two-dimensional integral equations that describe ground wave propagation are presented and compared. The one-dimensional equation is shown to be inaccurate at low frequencies for obstacles narrower than about 10 km and typical pathlengths. In such cases, the two-dimensional equation is needed to account properly for the signal's dependence on obstacle width, recovery at long distances, and transverse diffraction pattern. The one- and two-dimensional solutions approach each other at large distances beyond very wide obstacles.

Probable Position of the Outer Wing of the Ryôke Metamorphics in Southwest Japan

A new idea is here introduced for elucidation of a problem, left unsolved for a long time, concerning three geological features characterizing Southwest Japan.1. The Ryoke metamorphics have their axial zone of gneisses and associated granitic rocks close to the Median Dislocation Line of Southwest Japan along its northern side. The grade of metamorphism decreases gradually northward through the inner or north wing of various schists and hornfelses finally to non-metamorphosed Palaeozoic rocks. In contrary, there is no trace of its outer or south wing preserved at least along the greater part of the Median Dislocation Line.2. In the Outer Zone of Sikoku, conglomerates in various Mesozoic formations are often stated to contain, sometimes even profusely, water-worn gravels of the rocks similar to the Ryoke metamorphics and associated granitic rocks, in strong contrast to the total absence of gravels of the rocks similar to the Nagatoro metamorphics, in spite of the present geographical situation of the sites of the conglomerates lying much nearer to the terrain of the Nagatoro metamorphics than to that of the Ryoke.3. Likewise, very attractive is the total absence of detritus of the Nagatoro metamorphics and the abundance of non-metamorphosed Palaeozoic rocks, Ryoke metamorphics and associated granitic rocks in the Upper Cretaceous Izumi sandstone, which occupies a narrow terrain be tween the northern terrain of the Ryoke metamorphics and the southern terrain of the Nagatoro metamorphics.All these geological accounts can easily be explained, the writer believes, only by assuming that the outer wing of the Ryoke metamorphics once occupied a much higher level above the Nagatoro metamorphics, with a fairly wide intervention of feebly and non-metamorphosed Palaeozoic rocks, in the present terrain of the Nagatoro metamorphics.