Center manifold reduction for large populations of globally coupled phase oscillators

A bifurcation theory for a system of globally coupled phase oscillators is developed based on the theory of rigged Hilbert spaces. It is shown that there exists a finite-dimensional center manifold on a space of generalized functions. The dynamics on the manifold is derived for any coupling functions. When the coupling function is $\sin \theta$, a bifurcation diagram conjectured by Kuramoto is rigorously obtained. When it is not $\sin \theta$, a new type of bifurcation phenomenon is found due to the discontinuity of the projection operator to the center subspace

Seismic collapsing behaviour of one-story wooden structure with thatched roof under strong earthquake ground motion

In Japan, there has existed a serious problem on seismic retrofit for a lot of one-story wooden structures such as temples and shrines in famous tourist resort areas, which were built by a Japanese traditional framedconstruction method and have some types of thatched roof instead of tiles. In order to investigate the seismic behaviour of an old one-story thatched roof wooden structure, “Yakushi-doh”, 3-D non-linear collapsing process analysis of Yakushi-doh structure was conducted against a strong earthquake ground motion with the Japan Meteorological Agency seismic intensity of “6 upper” level. A non-linear behaviour of timber elements in the wooden structure during a strong earthquake ground motion can be simulated by this 3-D non-linear collapsing process analysis based on the Distinct Element Method. The effect of the post fixing condition under wooden structure floor on seismic response of Yakushi-doh structure was numerically investigated in this paper

Seismic Collapsing Process Analysis of One-story Thatched Roof Wooden Structure under Strong Earthquake Ground Motion

In Japan, there has existed a serious problem on seismic retrofit for a lot of one-story wooden structures such as temples and shrines in famous tourist resort areas, which were built by a Japanese traditional framed-construction method and have some types of thatched roof instead of tiles. In order to investigate the seismic behaviour of an old one-story thatched roof wooden structure, "Yakushi-doh", 3-D non-linear collapsing process analysis of Yakushi-doh structure was conducted against a strong earthquake ground motion with the Japan Meteorological Agency seismic intensity of "6 upper" level. A non-linear behaviour of timber elements in the wooden structure during a strong earthquake ground motion can be simulated by this 3-D non-linear collapsing process analysis based on the Distinct Element Method. The effect of the post fixing condition under wooden structure floor on seismic response of Yakushi-doh structure was numerically investigated in this paper

Seismic Performance of One-storey Thatched Roof Wooden Structure Against a Strong Earthquake Ground Motion

In order to investigate the seismic behaviour of an old one-storey thatched roof wooden structure, 3-D non-linear collapsing process analysis of this wooden structure was conducted against a strong earthquake ground motion with the Japan Meteorological Agency seismic intensity of "6 upper" level. A non-linear behaviour of timber elements in the wooden structure during a strong earthquake ground motion can be simulated by this 3-D non-linear collapsing process analysis based on the Distinct Element Method. The effect of the post fixing condition under wooden structure floor on seismic response of this wooden structure was numerically investigated in this paper

Seismic Collapsing Behaviour of Three-story Wooden House under Strong Earthquake Ground Motion

In order to investigate the seismic behaviour of an old three-story wooden house, 3-D non-linear collapsing process analysis of this wooden house was conducted against a strong earthquake ground motion. A non-linear behaviour of timber elements in the wooden structure during a strong earthquake ground motion can be simulated by this 3-D non-linear collapsing process analysis based on the theory of the Distinct Element method

Influence of polymer molecular weight on the properties of in situ synthesized silver–methylcellulose nanocomposite films with a CO₂ laser

We investigate the influence of polymer molecular weight on the properties of silver–methylcellulose (Ag–MC) nanocomposite films synthesized by the irradiation of a CO₂ laser. Although the reduction power of MC with a smaller molecular weight turns out to be stronger than that with a larger molecular weight in the solution phase, we do not see such a clear difference when MC is in the matrix phase. For the 30 s irradiation at the laser power of 0.8 W, the size of Ag nanoparticles (NPs) in the two types of MC matrix is similar, and it is about 30 nm. However, for the longer irradiation time at the same laser power, aggregation of Ag NPs set in, and it is more serious for the Ag–MC film with MC of larger molecular weight. We also carry out the antibacterial test with the Ag–MC films, and find that the Ag–MC film synthesized at the lower laser power and shorter irradiation time generally exhibits a stronger antibacterial effect

経験的手法による地震動特性の評価と計測震度予測への適用

取得学位：博士(工学)，学位授与番号：博甲第830号，学位授与年月日：平成18年3月22日,学位授与年：200

経験的手法による地震動特性の評価と計測震度予測への適用

[研究概要