On Estimation of the Maximum Structural Response to Random Earthquake Motion from Response Envelope

A method of analysis is discussed to obtained the probability distribution of the maximum response of structures subjected to a non-stationary random earthquake motion. The envelope of the narrow band response of structures is analyzed, from which an approximate result for the probability distribution of the maximum response is derived. The accuracy of the analytical results is chekced by means of a numerical simulation

Probability Distribution of the Maximum Response of Structures Subjected to Nonstationary Random Earthquake Motion

Presented are the results of a theoretical analysis of the statistical properties of the maximum structural response to nonstationary random earthquake motion. Two approximate methods were developed to obtain the probability distribution of the maximum earthquake response on the basis of the pure-birth process equation and the peak envelope distribution, which should be adopted alternatively depending on the range of the structural and excitation parameters. Also discussed is a concept of structural design for random earthquake loads on the basis of the numerical results

On the Probability Distribution of the Number of Crossings of a Certain Response Level in Random Vibration

Presented are the results of analysis of a kind of threshold-value crossing problem in random vibration. Probability of crossings of a certain response level by a given number of times is formulated in terms of the “n-th passage time density”, from which approximate solutions are derived under the renewal process approximation. Discussions are made in comparison with the simple Poisson process approximation

A Renewal Process Model for Use in Seismic Risk Analysis

A model of random occurrence of earthquakes using a renewal process is proposed on the basis of the catalogue of historical earthquakes for Kyoto, Japan. The model accounts for the variation of annual occurrence rate depending on the intervals between successive earthquakes. It can incorporate widely recognized nonstationary features of earthquake occurrences that can not be explained with the conventional simple Poisson process models. By using the renewal process model, called herein the double Poisson process model, one can estimate the probability of future earthquake occurrences in terms of the conditional probability based on the time since the last earthquake. Numerical results are presented for the Kyoto area

Simplified Formula for Axial Strains of Buried Pipes Induced by Propagating Seismic Waves

Pipe strains developed in buried straight pipes by horizontally propagating seismic waves are analyzed. Extensive discussion is made for the general slippage conditions between soils and pipes, as well as for the arbitrary angle of incidence of the longitudinal and transverse waves relative to the pipe axis. After the pipe strain solutions and their upper and lower bounds are obtained for the given values of the angle of incidence, solutions for the maximum pipe strains with unknown angles of incidence are discussed. In particular, simple approximate closed-form solutions for the maximum pipe strains developed herein should be useful for practical applications

A Statistical Study of the Maximum Ground Motion in Strong Earthquakes

This paper presents the results of a theoretical analysis of the statistical properties of the maximum ground motions in strong earthquakes. The statistical model of earthquakes is proposed so as to be consistent with the past records of occurrence of earthquakes and with strong motion accelerograms, on the basis of which the methods are discussed to find the probability distribution of the maximum ground motion in a single earthquake and that for a certain future period. Numerical results are given in the form of charts and seismic maps

Reliability Theory of Structures with Strength Degradation in Load History

The theory of structural reliability is developed for repeated loads with due consideration for strength degradation dependent on the load intensity. The probability distribution of the residual strength of the structure is treated as such that modified by successive application of loads in the sense of both the non-failure effect and the strength-degradation effect. The numerical results of this study show some essential and interesting aspects as to the change in the structural strength and the reliability function through applications of repeated loads

Seismic Hazard Estimation Based on Non-Poisson Earthquake Occurrences

A non-Poisson earthquake occurrence model for seismic hazard estimation is developed to account for the periodicity and the nonstationarity in seismic activities. The model consists of a renewal process model for major fault systems and a nonstationary Poisson-type model for secondary seismic sources, the latter being dominated by the former. The model is identified on the basis of the historical earthquake data for the Kinki District in the western part of Japan, containing the Kyoto-Osaka-Kobe metropolitan area. A simulation model for seismic hazard estimations (ground acceleration and velocity are dealt with) is then developed by combining the non-Poisson earthquake occurrence model and probabilistic attenuation rules. On the basis of the results of the simulation, the significance of the periodicity and the nonstationarity of seismic activities in assessing the seismic risk is discussed

Effect of Ground Motion Duration on Seismic Design Load for Civil Engineering Structures : Development of Equivalent Ground Acceleration (EQA)

The effect of ground motion duration on seismic loads for structural design is studied in terms of the equivalent ground acceleration (EQA). EQA is obtained by multiplying the peak ground acceleration (PGA) by a reduction factor (EQA factor), which takes into account the peak response ratio relative to its standard values and the effective level of response affecting structural failure. Both are evaluated in connection with the duration of the input ground motion. EQA is considered to be a direct measure of destructiveness of earthquake ground motion, and will provide straightforward information for determining and interpreting the design seismic load. An EQA model is proposed and formulated. On this basis, the effect of a strong motion duration on the seismic design load is discussed, using numerical results for recorded accelerograms. Statistical models are developed so that EQA can be estimated on a hand-caluculator basis

Animal Exercise: A New Evaluation Method

At present, Animal Exercise courses rely too much on teachers’ subjective ideas in teaching methods and test scores, and there is no set of standards as a benchmark for reference. As a result, students guided by different teachers have an uneven understanding of the Animal Exercise and cannot achieve the expected effect of the course. In this regard, the authors propose a scoring system based on action similarity, which enables teachers to guide students more objectively. The authors created QMonkey, a data set based on the body keys of monkeys in the coco dataset format, which contains 1,428 consecutive images from eight videos. The authors use QMonkey to train a model that recognizes monkey body movements. And the authors propose a new non-standing posture normalization method for motion transfer between monkeys and humans. Finally, the authors utilize motion transfer and structural similarity contrast algorithms to provide a reliable evaluation method for animal exercise courses, eliminating the subjective influence of teachers on scoring and providing experience in the combination of artificial intelligence and drama education