Stormwater Infrastructure Resilience Assessment against Seismic Hazard Using Bayesian Belief Network.

Resilient stormwater infrastructure is one of the fundamental components of resilient and sustainable cities. For this, the resilience assessment of stormwater infrastructure against earthquake hazards is crucial for municipal authorities. The objective of this study is to develop a resilience assessment framework for stormwater pipe infrastructure against seismic hazards. A Bayesian belief network (BBN)-based stormwater infrastructure resilience model is constructed based on the published literature and expert knowledge. The developed framework is implemented in the city of Regina, Canada, to assess the city's stormwater pipe infrastructure resilience. The outcome of the model indicates that proposed BBN-based stormwater infrastructure resilience model can effectively quantify uncertainties and handle the nonlinear relationships between several reliability and recovery factors. The model is also capable of identifying the most sensitive and vulnerable stormwater pipes within the network.

Dynamical scaling in two-dimensional quenched uniaxial nematic liquid crystals.

The phase-ordering kinetics of the two-dimensional uniaxial nematic has been studied using a cell dynamic scheme. The system after quench from T=infinity was found to scale dynamically with an asymptotic growth law similar to that of the two-dimensional O(2) model (quenched from above the Kosterlitz-Thouless transition temperature), i.e., L (t) approximately [t/ln (t/ t(0) ) ](1/2) (with nonuniversal time scale t(0) ). We obtained the true asymptotic limit of the growth law by performing our simulation for a sufficiently long time. The presence of topologically stable 1/2 -disclination points is reflected in the observed large-momentum dependence k(-4) of the structure factor. The correlation function was also found to tally with the theoretical prediction of the correlation function for the two-dimensional O(2) system.

Phase transitions in two planar lattice models and topological defects: a Monte Carlo study.

Monte Carlo simulation has been performed in the planar P2 and P4 models to investigate the effects of the suppression of topological defects on the phase transition exhibited by these models. Suppression of the 1/2 defects on the square plaquettes in the P2 model leads to complete elimination of the phase transition observed in this model. However, in the P4 model, on suppressing the single 1/2 defects on square plaquettes, the otherwise first order phase transition changes to a second order one which occurs at a higher temperature, and this is due to the presence of a large number of 1/2 pair defects which are left within the square plaquettes. When we suppressed these charges too, complete elimination of the phase transition was observed.

Local and global persistence exponents of two quenched continuous-lattice spin models.

Local and global persistence exponents associated with zero-temperature quenched dynamics of two-dimensional XY model and three-dimensional Heisenberg model have been estimated using numerical simulations. The method of block persistence has been used to find the global and local exponents simultaneously (in a single simulation). Temperature universality of both the exponents for three-dimensional Heisenberg model has been confirmed by simulating the stochastic (with noise) version of the equation of motion. The noise amplitudes added were small enough to retain the dynamics below criticality. In the second part of our work we have studied scaling associated with correlated persistence sites in the three-dimensional Heisenberg model in the later stages of the dynamics. The relevant length scale associated with correlated persistent sites was found to behave in a manner similar to the dynamic length scale associated with the phase ordering dynamics.