Akinori Tani

Intelligent fuzzy optimal control of building structures

Abstract This paper describes an optimal adaptive and predictive control system and its digital simulations for a five-degree-of-freedom system subjected to earthquake loading. In this system, an active mass driver system and an equivalent variable mass system are employed as an active control method. Prediction of earthquake input and structural identification are performed by using neural networks based on the error back-propagation method. To get appropriate training data for structural identification, the genetic algorithm is employed. Optimization is performed by means of macimizing decision. In maximizing decision, optimal target control variables are determined by using assumed membership functions of target responses. Results of digital simulations show the effectiveness of the proposed control system.

Real time prediction of earthquake ground motions and structural responses by statistic and fuzzy logic

To realize an optimum and adaptive control of structures subjected to earthquake loading, the prediction of uncertain input waves and the identification of uncertain structural characteristics are needed. In this study, the following real-time methods are examined numerically and statistically: prediction of earthquake waves by conditioned fuzzy set rules, and prediction of structural responses by the piecewise linearity hypothesis. The effectiveness of these two methods is verified by the comparison between real and predicted values and finally by standard deviations.<<ETX>>

Seismic response control tests and simulations by fuzzy optimal logic of building structures

This paper outlines shaking table tests and their results for an active seismic response control system that uses fuzzy optimal logic (FOL). The test results confirmed the validity of the vibration control effect of this seismic response control system. The results of this study lead to two conclusions, that the effectiveness of this FOL control system can be increased by modifying the membership function, and that the results of seismic response control tests can be qualitatively evaluated by simple simulation methods.

Simulation of Urban System ``As It Could Be'' by Multiagent Model

In this paper, a multi-agent system is employed for modeling an urban system. The supposed urban system is composed of three urban agents, i.e. household, base, and service agents. Agents interact each other economically and pay land rents and moving costs. Agents which cannot adapt to the urban system disappear. Agents which survive in the system create new agents and their decision-making rules are followed to the new ones. Using this model, urban land-use pattern is simulated with three different distance constraints. Land-use patterns and rules are compared.

Fuzzy optimal seismic control systems of buildings-In case of active equivalent variable mass system

Seismic active structural control is discussed. An optimal adaptive and predictive control system by using the equivalent variable mass system is proposed to realize an intelligent control system by fuzzy logic. Its digital simulations about a single-degree-of-freedom system are shown. The effectiveness of this system is verified by the comparison between normalized probability mass functions and assumed membership functions and finally by standard deviations.<<ETX>>

A paradigm of intelligent fuzzy networks

For engineering planning and design, a paradigm of intelligent fuzzy networks is proposed which consists of fuzzy systems composed of inputs, states, and outputs. Each of the fuzzy systems can be replaced by a neural network, fuzzy confluence rule, fuzzy identifier, and so on, which can learn given knowledge or experience by determining their weighting factors and/or coefficients. After learning, intelligent fuzzy networks have intelligent functions such as evaluation, optimization, and decision-making.<<ETX>>

Fundamental Tests on a Structural Health Monitoring System for Building Structures Using a Single-board Microcontroller

Abstrct Aiming at the extension of structural health monitoring systems, a new monitoring system with low cost and easy installation was developed in this study. The proposed system includes MEMS acceleration sensors for measuring, a single-board microcontroller GR-SAKURA for processing, and a wireless device, XBee-PRO, for communicating. Acceleration data are collected by microcontroller and transferred by wired or wireless devices to a PC for real-time monitoring. To verify the measuring performance of the proposed system, fundamental shaking table tests were conducted on a small-scale three-story specimen. Data collection and measuring accuracy were verified. The system′s applicability to structural health monitoring systems was assessed. Experimental results showed that the response accelerations and natural frequencies of the specimen measured using the proposed system coincided well with those measured using a conventional data logger. GR-SAKURA has sufficient processing capability. XBee-PRO was confirmed to satisfy basic communication requirements equal to a wired system. Therefore, the proposed system is applicable for structural health monitoring systems with high cost-performance and simple construction.

Fundamental Test of Seismic Information and Building Damage Data Gathering System using OSHW with Wireless Sensor Network

To cope with a large disaster such as that caused by a large earthquake, it is necessary to gather seismic information and building damage data. This paper describes open source hardware (OSHW) with various sensors and a wireless communication system used as a new device to measure the strength of an earthquake and the extent of building damage. The OSHW assessed in this study is inexpensive and readily accessible. Therefore, the spread of wireless sensor network with the OSHW is expected. For this study, an acceleration sensor is used to conduct the following examinations. First, a component of OSHW with the wireless sensor network is explained, as are its specifications. Secondly, simple and extensive applications for the system for gathering seismic information and building damage data are proposed. Thirdly, future subjects of these applications are defined. Several fundamental test results are presented. Finally, the effectiveness of this seismic information gathering system is discussed.

Proposal of a new plane shape of an opera house—optimized by genetic algorithms

The horseshoe‐shaped theater has been the main shape from historical circumstances. However, from acoustical points of view, the rationality of the peculiar plane shape is not yet verified more than historical refinement. In this study, in order to make the theater shape more acoustically excellent, optimization for temporal and spatial factors in the theory of the subjective preference was made using genetic algorithms (GAs) by operating the positions of side walls. Results reconfirm that the plane shape of the optimized theater is a leaf shape, which has been verified to be acoustically rational in a concert hall. And, further possible shapes are also offered.

A study on the estimation method of target design engineering quantity considering client satisfaction

Based on the reflection of Hanshin Awaji big earthquake disaster, the target of this study is the development of performance based design method from the point of view of clients. That development aims to propose the estimation method of the rational target design engineering quantity that gives higher performance of satisfaction against the earthquake by using soft-computing method. In this study, the story deformation is adopted as a design engineering quantity.