Weijun Guo

Learn More
Our deteriorating civil infrastructure faces the critical challenge of long-term structural health monitoring for damage detection and localization. In contrast to existing research that often separates the designs of wireless sensor networks and structural engineering algorithms, this paper proposes a cyber-physical co-design approach to structural health(More)
The Monte Carlo simulation code CEARPPU has been improved to obtain better accuracy for predicting pulse-height spectra measured at high counting rates. Experimental verification was carried out by measuring an Fe-55 spectrum with a Si(Li) X-ray spectrometer. Based on the spectrum measured at low counting rate, which is considered to be the " true "(More)
An integrated Monte Carlo-Library Least-Squares (MCLLS) System has been developed and implemented to model the complete spectral response of energy-dispersive X-ray fluorescence (EDXRF) spectrometers and perform an inverse elemental analysis by an iterated Library Least-Squares method when an initial guess is provided. This software is a visualization(More)
The EDXRF inverse problem is solved by first correcting (if necessary) the sample pulse-height spectrum for pulse pileup with the Monte Carlo code CEARPPU. Then the Monte Carlo-Library Least-Squares (MCLLS) approach is used. This approach consists of using a forward Monte Carlo code (CEARXRF) that is capable of simulating the complete non-linear(More)
The Monte Carlo – Library Least-Squares (MCLLS) approach has now been developed, implemented, and tested for solving the inverse problem of EDXRF sample analysis. It consists of a linear library least-squares (LLS) code and a comprehensive Monte Carlo code named CEARXRF that is capable of calculating the unknown sample spectrum, all the elemental library(More)
There is a wide variation in sensitivity to lead (Pb) exposure, which may be due to genetic susceptibility towards Pb. We investigated whether a polymorphism (rs1800435) in the δ-aminolevulinic acid dehydratase (ALAD) gene affected the toxicokinetics and toxicodynamics of Pb. Among 461 Chinese Pb-exposed storage battery and 175 unexposed workers, allele(More)
The health of civil structures is very important and sometimes life-critical. While there are different ways to monitor their health, wireless sensor network (WSN) has the advantage of easy deployment and low cost, which make it feasible for most structures. We designed and implemented a system to localize damages on structures with a WSN by detecting the(More)
In previous work, the main interfering background for the in vivo lead in bone measurement was found to be from back-scattered Compton and Rayleigh source photons, which is, therefore, also the main problem for the improvement of sensitivity. Based on the physics of atomic transition, certain fractions of the characteristic K-series X-rays and L-series(More)
  • 1