This paper analyzes the effects of the Great Kanto Earthquake of 1923 upon Japan, placing emphasis on subsequent social changes. "The mobilization of citizens" for emergency was planned in larger cities, such as Osaka and Tokyo, on the basis of the Great Kanto Earthquake experience. "The mobilization of citizens" served as a slogan to mobilize citizens in a systematic way, in order to maintain public order, extinguish fires, rescue the injured, etc., in the event of natural disaster or attack from the air. The tragic experiences of the Great Kanto Earthquake, combined with analogous experiences suffered by European cities, which had been subjected to air raids during WWI, led directly to the first Japanese investigation into measures to prevent disasters resulting from possible air attack. After the Great Earthquake it became a matter of urgent necessity to come up with measures to prevent such disasters. Though it was of course only in the late 1930's that full-scale air defense measures were devised, their origin can be traced back to the Great Kanto Earthquake. Historians have generally regarded "the mobilization of citizens" in the 1920's merely as part of the mobilization plans made by the Army. In contrast, this paper stresses the natural disaster prevention aspect of "the mobilization of citizens," focusing on the role played by Japan's Osaka and Tokyo local governments, because it was the local governments which prepared rescue plans and organized citizens' rescue teams. In the 1930's these plans (and the rescue teams formed on their basis) were drawn upon when the Army prepared its own contingency measures against air attacks. To sum up, this paper is a case study of one important way in which WWI and the Great Kanto Earthquake influenced Japanese history.

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The authors tried the theoretical analysis on the motions, hull surface pressures and transverse strength of a gigantic oil tanker in regular waves.
In the first place, the ship motions in regular waves from different directions were analysed by assuming the coupled equations of heaving and pitching motions and those of swaying, yawing and rolling motions based upon the modified strip theory. The non-linear roll damping was introduced into the latter coupled equations of motion.
In the second place, the hydrodynamic pressures induced on the hull surface were evaluated theoretically by using the solutions of ship motions.
Finally, the transverse strength calculations were performed for several cases of the ship in waves by using the obtained hull surface pressures and the estimated cargo oil pressures.
The large hydrodynamic pressures were found in beam and quartering waves, which produced the large bending moments at the deck corner, bilge and bottom of longitudinal bulkhead in the transverse ring.

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