Yoichiro Morita

Experimental Study on Mechanical Properties of Ultra-High-Strength Concrete with Low-Autogenous-Shrinkage

A new type of low-autogenous-shrinkage ultra-high-strength concrete with a compressive strength of more than 150 MPa has been developed for use in prestressed concrete structures. By using artificial aggregate with coal ash that has an internal-curing effect, in addition to a conventional expansive agent and shrinkage reducing agent, the effects of autogenous shrinkage reduction and compressive strength were investigated experimentally. The experimental results showed that although the artificial aggregate with coal ash causes a loss of compressive strength, it greatly contributes to the reduction of autogenous shrinkage; autogenous shrinkage of ultra-high-strength concrete can be effectively reduced by adjusting the quantity of aggregate used and the combination of admixtures used. The mechanical properties of ultra-high-strength concrete with low-autogenous-shirnkage were also evaluated, and it was confirmed that currently used estimation formulas are applicable.

CIM-Based Resource Information Management for Integrated Access Control Manager

An architecture for CIM-based integrated access control middleware is proposed. The proposed architecture employs CIM standards for managing several access control modules for different resources uniformly in consolidated server environments. CIM standards allow the user of the middleware to look up the target resource information through the common interface, to describe abstract policy with grouping the same type of resources together, and to translate the abstract policy to detailed configurations for each access control module automatically. We evaluated the feasibility of the proposed architecture by a pilot implementation for file access control systems. According to the findings of the evaluation, we propose an extension of the CIM_Directory class to improve operations for exploring directories on user interfaces of the middleware.