Markov Chain transition probability modeling of radon gas records and future projection possibility determination

Markov Chain models serve two purposes firstly, subdivide the main data based on the mean value and one and two standard deviation plus and minus values around the mean value. The second stage of modeling, after calculating the transition probabilities between these categories from the available data, is completed by repeatedly multiplying the categorization date groups until the steady-state transition probability values are obtained. This procedure provides a convenient modeling approach for radon gas transient measurement records. After a brief presentation of Markov Chain procedure in this paper, the application is carried out by considering five categories that lead to a better transition probability matrix. Such a matrix provides information about the probabilities of future transition at the radon data measuring station. In addition, it is possible to associate these transition probabilities with the possibility of an earthquake.AFA

Comparison of near- and far-fault ground motion effect on the nonlinear response of dam-reservoir-foundation systems

In this paper, it is aimed to compare the near- and far-fault ground motion effects on the nonlinear dynamic response of dams including dam-reservoir-foundation interaction. Two different types of dams, which are concrete arch and concrete faced rockfill dams, are selected to investigate the near- and far-fault ground motion effects on the dam responses. The behavior of reservoir water is taken into account using Lagrangian approach. The Drucker-Prager material model is employed in nonlinear analyses. Near and far-fault strong ground motion records, which have approximately identical peak ground accelerations, of Loma Prieta (1989) earthquake are selected for the analyses. Displacements, maximum and minimum principal stresses are determined using the finite element method. The displacements and principal stresses obtained from the analyses of dams subjected to each fault effect are compared with each other. It is clearly seen that there is more seismic demand on displacements and stresses when the dam is subjected to near-fault ground motion. © 2009 Springer Science+Business Media B.V