RFID-Based Wireless Multi-Sensory System for Simultaneous Dynamic Acceleration and Strain Measurements of Civil Infrastructure

© 2001-2012 IEEE. In this paper, we develop a radio frequency identification (RFID)-based wireless multi-sensory infrastructure health monitoring (IHM) system that can simultaneously measure dynamic acceleration and strain. The system consists of a novel multi-sensor integrated semi-passive ultra-high frequency (UHF) tag antenna that can be mounted on civil infrastructure elements; even made out of metal. The system is capable of measuring 3-axis dynamic acceleration and strain with spectral bandwidths of 40 Hz and 26.5 Hz, respectively. The natural frequency determination of infrastructure by the dynamic acceleration and strain measurements of the proposed system is accurate to 60 mHz. Benchmarking of the RFID-based wireless multi-sensory system is provided by comprehensive comparison of the results with measurements from a commercial wireless strain measurement system. The proposed system has 30 mHz natural frequency determination error when compared with dynamic strain measurement from the commercial system

The Unconventional Strength Towards STEM Cohort

Science, Technology, Engineering and Mathematics (STEM) play a critically important role in Australia’s ability to innovate, expand and remain a competitive force globally. Indeed, ensuring that the workforce has the relevant skills in sufficient quantities through a reliable educational pipeline is quite challenging and requires an understanding of how these skills are and will be used within the Australian economy. Moreover, successfully delivering these skills for a knowledge economy will depend not only on producing the correct number of graduates but also on the education system supplying graduates from under-utilised groups (i.e. women & indigenous people) and diverse backgrounds. Currently, millions of children and young people are not developing the required skills to participate effectively in STEM environments. Young indigenous and female groups, in particular, are deprived of the opportunities to build their skills, including STEM literacy that is valued towards career progression in traditionally male-dominated fields (i.e. engineering and construction). As this white paper outlines, the challenges are drawn from recent literature, and a comprehensive review of existing initiatives is presented based on the observations of key partners, including Western Sydney University, the Australian government, research sector, industry, policymakers and communities. However, to build the STEM capacity of graduates with the right knowledge, competencies and qualities, two-way collaboration between the communities, educational institutions (from an early age), Australian workplaces and the government is essential, as no single sector can entirely solve the current STEM skills shortage. Western Sydney University is well-positioned within the high-density indigenous areas to respond to these issues, particularly by monitoring, engaging and promoting all graduates with STEM qualifications to meet the demand from the economy. In fact, by supporting equity and diversity throughout the STEM cohorts, educational institutions not only drive innovation but also establish a thriving STEM-skilled workforce that is fit for the future

Antibacterial activity of eight invasive alien plants against selected multi-drug resistant microorganisms

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Measurement System with Accelerometer Integrated RFID Tag for Infrastructure Health Monitoring

This paper presents a measurement system for measuring dynamic acceleration of infrastructure remotely using semipassive radio-frequency identification (RFID) tag. This measurement is critical to the vibration-based method for infrastructure health monitoring. Design considerations of accelerometer integrated ultrahigh-frequency RFID tag and dynamic acceleration measurements through an RFID wireless link are discussed. Measurement results of the system for a structural specimen have shown that it is capable of acquiring data which provides the information of natural frequency of the structural specimen. Moreover, the system can distinctively identify the state changes of the structural specimen by natural frequency shifts. These results are benchmarked against the results obtained with two commercial systems. It is shown that the standard deviation of the measurement of the natural frequency is ±0.01 Hz which is very close to the standard deviation of the commercial measurement systems

Monitoring of the coalesced ice ball in cryosurgery

In this paper we consider the ice ball formation in a multi-probe cryosurgical procedure. By representation of collocation polynomials and visualisation of individual ice ball formation the radius of thermal propagation from the cryoprobe tip centre can be investigated. This serves as the basis for optimisation of cryoprobe placement to the targeted tissue or the surgeon’s decision for the cessation of the freezing process during cryosurgery

Structural damage detection and localization using a hybrid method and artificial intelligence techniques

© The Author(s) 2019. In this article, an intelligent scheme for structural damage detection and localization is introduced by implementing a hybrid method using the Hilbert–Huang transform and the wavelet transform. First, the second derivatives of the Discrete Laplacian are computed on Hilbert spectrum parameters at each frequency coordinate, and then, in order to highlight the influence of damage on signals, the data are rescaled and weighted with respect to the variance to adjust the differences in amplitude at different scales. Afterwards, the anti-symmetric extension is applied to deal with the boundary distortion phenomenon. A two-dimensional map is created using the multi two-dimensional discrete wavelet transform. This generates the coefficient matrices of level 2 approximation and horizontal, vertical and diagonal details. Horizontal detail coefficients are used to localize damages due to its sensitiveness to any perturbation. Finally, the validity of the algorithm corresponding to various damage states, the single state damage and multiple state damage, is examined through experimental analysis. The results indicate that the proposed framework can effectively localize cracks on concrete and reinforced concrete beams and can provide reliable crack localization in the presence of noise up to 5% more than the expected noise. In addition, the detection problem is mapped to machine learning tasks (support vector machine, k-nearest neighbours and ensemble methods) to automate the damage detection process. The quality of the models is evaluated and validated using the features extracted from the horizontal detail coefficients. The numerical results show that the ensemble models outperform the other models with respect to accuracy, prediction speed and training time

Horizontal-to-vertical spectral ratio inversion using Monte Carlo approach and enhanced by Rayleigh wave dispersion curve

The inversion of Rayleigh dispersion curve has been used to estimate the Vs ground profiles (thickness of soil layers vs. shear wave velocity, Vs) of a site. These Rayleigh dispersion curves are usually retrieved using several geophones or sensors set up in linear array for active methods (e.g., Multichannel Analysis of SurfaceWaves-MASW), or linear array (Refraction Microtremor-ReMi) and/or geometrical array for passive methods. In recent years, the inversion of Horizontal-to-Vertical Spectral Ratio (HVSR) of passive microtremor records has become popular because only one station consisting of a 3 component sensor (one vertical and two horizontal components) is needed to carry out the field measurements.According to the results reported by several researchers, a more detailed estimation of shallow layers might be obtained when the HVSR inversion is applied. However, supplementary field surveys, such as Cone PenetrationTest (CPT), are needed to obtain reliable HVSR inversions, meaning that the characterisation of surface layers without supplementary geotechnical surveys are estimated with some uncertainties and should be avoided. In this paper, an attempt to estimate reliable overall Vs ground models is carried out from the HVSR inversion using the Monte Carlo approach and enhanced by the Rayleigh wave dispersion curve. As case study, a dynamically compacted area of the Penrith Lakes site is assessed by the proposed technique. From the results obtained at this site, a detailed Vs ground model resembling CPT record was obtained

Thermal modelling in a multi-probe cryosurgical procedure

Cryosurgical procedure utilises multiple probes positioned invasively into the body. The probe tip is brought in contact with the tissue, freezing it at a pre-determined low temperature. The process promotes tissue necrosis or death to cancer cells. Liquid Nitrogen (LN2) which is made to flow through the inner walls of the cryogenic probe is utilised in this research. The perennial issue concerning cryosurgery is the monitoring of the ice formation and thermal representation on the surrounding tissue. For instance, it is imperatively desirable to encroach the entire tumour volume with ice but also having conservative concern on the nearby healthy tissues. Freezing healthy tissues could pose undesirable side effects such as: incontinence and urethrorectal fistula brought about by freezing the urethra in cryosurgery of prostate cancer. A method of thermal modelling is introduced in this research by simulating the individual ice ball formation and setting the temperature contour level around the region of interest

Student learning experience in a new education environment during the COVID-19 pandemic

This paper presents results of a student survey carried out among Civil and Construction Engineering undergraduate students within the School of Engineering, Design and Built Environment at Western Sydney University. The survey investigated the learning experience of students and the effectiveness of new educational processes implemented during the COVID-19 pandemic. Both quantitative and qualitative approaches were employed to examine the perceptions of students on online teaching modes. The survey results indicated some positive features of online teaching such as flexibility, comfortable educational environments and efficient time utilisation. However, students also found many challenges such as network instability, distractions, lack of engagement and mental stress. The identified areas of improvement were closely related to these challenges. The survey results highlighted that most students were satisfied with the teaching strategies and assessment methods. Improved and effective teaching methodologies for students to achieve better learning outcomes are proposed and discussed