Publications

We postulate a spatiotemporal multilevel model and estimate using forward search algorithm and MLE imbedded into the backfitting algorithm. Forward search algorithm ensures robustness of the estimates by filtering the effect of temporary structural changes in the estimation of the group-level covariates, the individual-level covariates and spatial parameters. Backfitting algorithm provides computational efficiency of estimation procedure assuming an additive model. Simulation studies show that estimates are robust even in the presence of structural changes induced for example by epidemic outbreak. The model also produced robust estimates even for small sample and short time series common in epidemiological settings. 

We propose a method that integrates bootstrap into the forward search algorithm in the construction of robust confidence intervals for elements of the eigenvectors of the correlation matrix in the presence of outliers. Coverage probability of the bootstrap simultaneous confidence intervals was compared to the coverage probabilities of regular asymptotic confidence region and asymptotic confidence region based on the minimum covariance determinant (MCD) approach through a simulation study. The method produced more stable coverage probabilities for datasets with or without outliers and across several sample sizes compared to approaches based on asymptotic confidence regions.

During strong earthquakes, reinforced concrete (RC) structures experience cyclic lateral loads that result to degradation in load-carrying capacity, and failure of columns in shear and/or flexure. This study presents a simple hysteretic hinge model that may be used in displacement-based analysis of RC columns, classified as flexure critical, shear critical, and shear-flexure critical, subjected to cyclic loads. The proposed hinge model made up of zero-length nonlinear springs can simulate the hysteretic behavior of reinforced concrete material in axial, shear, and flexure. The nonlinear parameters of the springs were derived from geometric and material properties of the column and estimated using Response-2000 software. Pushover analysis and response to cyclic loading were performed using the Open System for Earthquake Engineering Simulation (OpenSees) program and validated by comparing the force-displacement response of select forty-three RC columns available in the PEER Structural Performance Database. Results show that for the six rectangular columns, the numerical experiments using the proposed hinge model and the actual force-displacement curves gave R- squared values greater than 0.80 signifying good agreement of results. Therefore, it was concluded that the model can reasonably replicate nonlinear behavior of shear-, shear-flexure, and flexure-critical columns subjected to cyclic loading and, therefore, may be used to assess performance of actual RC columns.

Keywords—hinge model, reinforced concrete, performance assessment, OpenSees, column

This book proposes entanglement as a useful idiom for understanding the contemporary Manila theatre. Drawing on its Tagalog counterpart, buhol-buhol, entanglement is conceived not only as a juxtaposition among elements, but also as a process of muddling and snaring. Taken together, these affirm the entangled character of contemporary Manila theatre in overlapping representations, histories, relationships and genres, while at the same time marking some problematic limitations in the treatment of chosen subjects by Manilan artists. The reason for this is that while these entanglements render Manila theatre far more complex than the accusations of mimicry and inauthenticity frequently leveled at Filipino culture, artists are often caught up in a more intractable buhol-buhol than they are willing or able to recognize. Four figures of buhol-buhol are identified in this book: pista (fiesta), kapuluan (archipelago), patibong (trap), and nangingibang-bayan (overseas-worker). In conceptualizing these figures of entanglement, the discussions start by illustrating their materiality and performativity before proceeding to reflections about how these are directed towards the complexity of Manila theatre.

High aspect ratio silver nanowires (Ag NWs) were successfully synthesized by CuCl2-mediated synthesis. Scanning electron microscopy (SEM) and X-Ray diffraction were employed to investigate the morphology and structure of the Ag products, respectively. Suspensions of Ag NW in ethanol were coated on glass substrates by Meyer rod coating to fabricate transparent conducting electrodes (TCE’s). The electrodes were then plasma treated at a power of 75 W. The effects of increasing plasma treatment time and oxygen exposure on the sheet resistance of the transparent electrodes were investigated. A sheet resistance of 8 $Ømega$/sq with an optical transmittance of 80 % at 550nm was obtained for an electrode with a nanowire density of 0.18 mg/cm2 after 5 mins of plasma (Ar) exposure.