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This paper reports the scheme of a research project funded by the Ministry of Land， Infrastructure， Transport and Tourism (MLIT) from the fiscal year of 2012 to 2014 under the title of "Development of base isolation device complied with the ultimate strength design code." The theoretical prediction tells us a new approach to develop a highly stable laminated rubber bearing that has a constant buckling load even under large lateral displacement. Relatively high shear stiffness makes it more stable and the height of the bearing should be longer than its diameter. They are the newly discovered theoretical buckling stability criteria from the previous studies conducted by the author’s research team. The experimental studies in this project show the compatibility with the theoretical prediction and highly linear loaddisplacement relationship under large deformation. The performance of the newly developed device satisfies the requirement of the ultimate strength design code, if the ground condition of the target building is normally solid enough to prevent liquefaction. The theoretically predicted buckling stability of the laminated rubber bearings has been experimentally verified by the specimens of this project.

This paper discusses the eigenvalue problem of a nonlinear differential equation that governs the stability of a shear bending column under extremely large deformation. What is taken into consideration is the geometrical nonlinearity while the material is supposed to be linear. The reason of a superbly stable buckling behavior of a slender rubber bearing is physically explained by pointing out the analogy that is similar to the nonlinear wave propagation expressed in KdV equation. The nonlinear boundary condition and the nonlinear term of the differential equation cancel each other and make the associated eigenvalue rather constant. In other words, as far as the material is supposed to be linear, the column does not buckle no matter how large the deformation is. This theoretical prediction is experimentally verified and successfully applied to a base isolation system of a lightweight structure.

A comparison study of single-, bi-, and tri-layer resist (SLR, BLR, and TLR, respectively) process was investigated. The goal of this study is to clarify the advantage of each process for the pattern transfer etching process. Conventional ArF photoresist and bottom anti-reflective coating process were applied to SLR. Novel silsesquioxane (SSQ) resist and spin-on organic hard mask (SOHM) were used for BLR process. The SSQ consists of siloxane backbone which contains three components, protective group, solubility control group, and higher silicon containing group to increase etch selectivity to SOHM. The main polymer in SOHM contains naphthalene type unit, for both anti-reflective and etch-durable properties. SOHM layer is highly cross-linked film with more than 85wt% carbon content which contributes to higher etch selectivity. A conventional ArF photoresist as an imaging layer, spin-on glass (SOG) as an intermediate layer, and the SOHM as a bottom layer were applied to TLR process. Multi-layer materials of each process were spin-coated on the stacks of cap-oxide/low-k/SiC on Si substrate and exposed with ArF 0.75NA scanner for 100nm line and space imaging. SLR showed better lithographic performance than BLR and TLR. However after pattern transfer etching process into SiOC layer, the different performance among each process has been observed. SLR process after pattern transfer etching showed severe surface roughness, striation and line width roughness (LWR). On the other hand, BLR and TLR showed significant improvement of pattern transfer performance. Multi-layer process can improve LWR during etching process.

Authors propose a method to identify the mass matrix of a large building structure by using a small active dynamic damper, or equivalently, an active tuned mass damper. We modify the acceleration feedback algorithm, which was once developed for improving the dynamic damper's performance, with a different objective. The advantage of the dynamic damper is its size: it is so small that there is a possibility that we could create an extra-small device for measuring the mass of a large structure. We review the physical meaning of the acceleration feedback, and then we use a single-degree-of-freedom model to explain how to operate the device to examine the weight of a primary structure. Then, we extend this method to a multi-degree-of- freedom model so that we can measure its effective modal mass with respect to the location where this device is placed. The identification of the mass matrix of a large structure can be completed as we shift the observing points and determine the associated effective mass. Several numerical studies are also carried out to certify the proposed method.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.