Science and Technology Studies Commons^™

Compressive Behaviour Of Square Fibre-Reinforced Polymer-Concrete-Steel Hybrid Multi-Tube Concrete Columns, Chun Wa Chan, Tao Yu, Shi Shun Zhang

Faculty of Engineering and Information Sciences - Papers: Part B

Fibre-reinforced polymer-concrete-steel hybrid multi-tube concrete columns are a new form of columns recently proposed at the University of Wollongong. An multi-tube concrete column consists of an external fibre-reinforced polymer tube and a number of circular internal steel tubes, with the space inside all the tubes filled with concrete. This article presents the first ever experimental study on square multi-tube concrete columns. The experimental program included a total of 14 stub column specimens tested under axial compression, with the test variables being the thickness of the external fibre-reinforced polymer tube, and the dimensions and configuration of the internal steel tubes. The …

Influence Of Steel Fibres On The Behaviour Of Rpc Circular Columns Under Different Loading Conditions, Ahmed Al-Tikrite, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

An experimental program was conducted to investigate the effect of inclusion of steel fibres on the behaviour of Reactive Powder Concrete (RPC) columns. Three different types of steel fibre were used: micro straight steel fibre (MF), macro deformed steel fibre (DF) and waste steel fibre (WF) recovered from discarded tyres. In addition, a hybridization of steel fibres was made up to produce waste-industrial hybridization (WHF) (MF, DF and WF). Twenty reinforced RPC column specimens were prepared and tested under axial concentric, eccentric and flexural loading. Results of testing demonstrated that the ultimate axial load and the corresponding axial deformation increased …

Mechanical Properties And Microstructure Of A Ti-6al-4v Alloy Subjected To Cold Rolling, Asymmetric Rolling And Asymmetric Cryorolling, Hai Liang Yu, Ming Yan, Jintao Li, Ajit R. Godbole, Cheng Lu, Anh Kiet Tieu, Hui Jun Li, Charlie Kong

Faculty of Engineering and Information Sciences - Papers: Part B

The mechanical properties of the Ti-6Al-4V alloy are significantly determined by the process used for manufacture. In this study, the mechanical properties of the Ti-6Al-4V alloy manufactured using cold rolling, asymmetric rolling and asymmetric cryorolling were characterized by subjecting it to the tensile test and the microhardness test. The evolution in the microstructure was studied using scanning electron microscopy, transmission electron microscopy as well as energy dispersive X-ray spectrometry. Results show that the Ti-6Al-4V alloy sheets subjected to asymmetrical cryorolling with low rolling speed ratio between the upper and lower rolls have the highest tensile strength and microhardness. The tensile …

Behaviour Of Carbon Fibre-Reinforced Polymer-Confined Hollow Circular Concrete Columns With Inner Polyvinyl Chloride Tube, Hussamaldeen Goaiz, Tao Yu, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Existing studies have shown that the use of an inner tube can significantly enhance the effectiveness of confinement in fibre-reinforced polymer-confined hollow columns. The inner tube used in the existing studies, however, generally had a large stiffness and also served as longitudinal reinforcement. The use of a stiff inner tube is inefficient in resisting bending for hollow columns with a relatively small void and may be unnecessary for constraining the inner surface of concrete. Against this background, this article presents the first experimental study on fibre-reinforced polymer-confined hollow columns with an inner polyvinyl chloride tube. The experimental program included a …

Efficient Cost Aggregation For Feature-Vector-Based Wide-Baseline Stereo Matching, Xiaoming Peng, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Engineering and Information Sciences - Papers: Part B

In stereo matching applications, local cost aggregation techniques are usually preferred over global methods due to their speed and ease of implementation. Local methods make implicit smoothness assumptions by aggregating costs within a finite window; however, cost aggregation is a time-consuming process. Furthermore, most existing local methods are based on pixel intensity values, and hence are not efficient with feature vectors used in wide-baseline stereo matching. In this paper, a new cost aggregation method is proposed, where a Per-Column Cost matrix is combined with a feature-vector-based weighting strategy to achieve both matching accuracy and computational efficiency. Here, the proposed cost …

Local Buckling Of Steel Plates In Concrete-Filled Steel Tubular Columns At Elevated Temperatures, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Local buckling remarkably reduces the strength of steel plates in rectangular thin-walled concrete-filled steel tubular (CFST) columns at ambient temperature. This effect is more remarkable at elevated temperature. However, there have been very limited experimental and numerical investigations on the local and post-local buckling behavior of steel plates in CFST columns at elevated temperatures. This paper presents numerical studies on the local and post-local buckling behavior of thin steel plates under stress gradients in rectangular CFST columns at elevated temperatures. For this purpose, finite element models are developed, accounting for geometric and material nonlinearities at elevated temperatures. The initial geometric …

A Construction For {0,1,-1} Orthogonal Matrices Visualized, N A. Balonin, Jennifer Seberry

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.

The Effects Of Forced Interpass Cooling On The Material Properties Of Wire Arc Additively Manufactured Ti6al4v Alloy, Bintao Wu, Zengxi Stephen Pan, Donghong Ding, Dominic Cuiuri, Hui Jun Li, Zhenyu Fei

Faculty of Engineering and Information Sciences - Papers: Part B

To achieve improved microstructure and mechanical properties, an innovative wire arc additive manufacturing (WAAM) process with forced interpass cooling using compressed CO₂ was employed in this study to fabricate Ti6Al4V thin-walled structures. The effects of various interpass temperatures and rapid forced cooling on deposition geometry, surface oxidation, microstructural evolution, and mechanical properties of the fabricated part were investigated by laser profilometry, optical microscopy (OM), scanning electron microscopy (SEM), hardness testing and mechanical tensile testing. Results show that the microstructural evolution and mechanical properties of the deposited metal are not greatly affected by an increasing interpass temperature, however, the deposited …

Shift-Tail Equivalence And An Unbounded Representative Of The Cuntz-Pimsner Extension, Magnus Goffeng, Bram Mesland, Adam C. Rennie

Faculty of Engineering and Information Sciences - Papers: Part B

We show how the fine structure in shift-tail equivalence, appearing in the non-commutative geometry of Cuntz-Krieger algebras developed by the first two listed authors, has an analogue in a wide range of other Cuntz-Pimsner algebras. To illustrate this structure, and where it appears, we produce an unbounded representative of the defining extension of the Cuntz-Pimsner algebra constructed from a finitely generated projective bi-Hilbertian module, extending work by the third listed author with Robertson and Sims. As an application, our construction yields new spectral triples for Cuntz and Cuntz-Krieger algebras and for Cuntz-Pimsner algebras associated to vector bundles twisted by an …

A New Elementary Proof Of Euler's Continued Fractions, Joseph Tonien

Faculty of Engineering and Information Sciences - Papers: Part B

A new elementary proof of Euler's continued fractions

The Impact Of Imaging Modality (Ct Vs Mri) And Patient Position (Supine Vs Prone) On Tangential Whole Breast Radiation Therapy Planning, Kylie L. Dundas, Elise M. Pogson, Vikneswary Batumalai, Geoff P. Delaney, Miriam M. Boxer, Mei Ling Yap, Verity Ahern, Christine Chan, Steven David, Marion Dimigen, Jennifer A. Harvey, Eng-Siew Koh, Karen Lim, George Papadatos, Elizabeth Lazarus, Joseph Descellar, Peter E. Metcalfe, Lois C. Holloway

Faculty of Engineering and Information Sciences - Papers: Part B

Purpose

The purpose of this study was to evaluate the impact of magnetic resonance imaging (MRI) versus computed tomography (CT)-derived planning target volumes (PTVs), in both supine and prone positions, for whole breast (WB) radiation therapy.

Methods and materials

Four WB radiation therapy plans were generated for 28 patients in which PTVs were generated based on CT or MRI data alone in both supine and prone positions. A 6-MV tangential intensity modulated radiation therapy technique was used, with plans designated as ideal, acceptable, or noncompliant. Dose metrics for PTVs and organs at risk were compared to analyze any differences …

Development And Evaluation Of An Mre-Based Absorber With Two Individually Controllable Natural Frequencies, Jie Yang, Shuaishuai Sun, J Chi, Donghong Ning, Haiping Du, Shan-Wen Zhang, Weihua Li, Shixin Mao

Faculty of Engineering and Information Sciences - Papers: Part B

Adaptive tuned mass absorbers, which are based on magnetorheological elastomer (MRE) have been widely accepted for vibration absorption due to their frequency shift capability. Wider frequency bandwidth indicates more effectiveness in reducing vibrations. In order to broaden the effective bandwidth of the MRE-based absorber, this study proposes a new design consisting of an eccentric mass. This design enables the absorber to have two natural frequencies: the rotational natural frequency and the translational one. These two natural frequencies can be controlled separately by adjusting the MRE stiffness and the eccentric length. This design not only broadens the effective bandwidth of the …

Position Control Of A Soft Prosthetic Finger With Limited Feedback Information, Solen Kumbay-Yildiz, Rahim Mutlu, Gursel Alici

Faculty of Engineering and Information Sciences - Papers: Part B

One of the challenging research questions in soft robotics is the establishment of valid mathematical models and control techniques under limited feedback conditions. A soft robotic system will typically have a continuum or monolithic body seamlessly embodying its actuation and sensing elements, accompanied by mechanical structure, and even the energy source, much like a biological system. In this study, we propose a relay sliding mode controller based on the input - output model (RSMC-IO), which is a simple but effective control approach that does not require a complete system model, to control the tip position of a soft prosthetic finger, …

Driver Intention Based Coordinate Control Of Regenerative And Plugging Braking For Electric Vehicles With In-Wheel Pmsms, Wenfei Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part B

Electric vehicles have been the focus of the automotive industry in recent years. However, relatively small driving range of electric vehicles makes it not be broadly adopted in the market. Regenerative braking is one of the most effective ways to extend the endurance of electric vehicles. To sufficiently utilise the regenerative braking of electric vehicles and explore the potential of the electric motor plugging braking capability to simplify the braking system structure and reduce the cost, a new braking strategy based on the driver's braking intention and motor working characteristics is proposed. Driver's braking intention is classified as the emergency …

A 3d Approach For The Visualization Of Network Intrusion Detection Data, Wei Zong, Yang-Wai Chow, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part B

With the increasing threat of cyber attacks, machine learning techniques have been researched extensively in the area of network intrusion detection. Such techniques can potentially provide a means for the real-time automated detection of attacks and abnormal traffic patterns. However, misclassification is a common problem in machine learning techniques for intrusion detection, and a lack of insight into why such misclassification occurs impedes the improvement of machine learning models. This paper presents an approach to visualizing network intrusion detection data in 3D. The purpose of this is to facilitate the understanding of network intrusion detection datasets using a visual representation …

Modeling Supply Network Configuration Problems With Varying Demand Profiles, Subodha Dharmapriya, Senevi Kiridena, Nagesh Shukla

Faculty of Engineering and Information Sciences - Papers: Part B

In this paper, we develop a novel multi-objective modeling approach to support supply network configuration decisions, while considering varying demand profiles. In so doing, we illustrate how such an approach could contribute to building supply network robustness and resilience. The proposed model entails two key objectives; minimizing lead time and cost across the supply network. The solution approach first employs a bidding mechanism to select a set of supply network entities that match with a given demand profile from a candidate pool of entities. It then applies the popular technique known as N on-dominated Sorting Genetic Algorithm-II to generate a …

Preferred Traces On C⁎-Algebras Of Self-Similar Groupoids Arising As Fixed Points, Joan Claramunt, Aidan Sims

Faculty of Engineering and Information Sciences - Papers: Part B

Recent results of Laca, Raeburn, Ramagge and Whittaker show that any self-similar action of a groupoid on a graph determines a 1-parameter family of self-mappings of the trace space of the groupoid C⁎-algebra. We investigate the fixed points for these self-mappings, under the same hypotheses that Laca et al. used to prove that the C⁎-algebra of the self-similar action admits a unique KMS state. We prove that for any value of the parameter, the associated self-mapping admits a unique fixed point, which is a universal attractor. This fixed point is precisely the trace that extends to a KMS state on …

The Impact Of Contour Variation On Tumour Control Probability In Anal Cancer, Michael Jones, Jarad Martin, Kerwyn Y. Foo, Patrick Estoesta, Lois C. Holloway, Michael Jameson

Faculty of Engineering and Information Sciences - Papers: Part B

Background: While intensity modulated radiotherapy (IMRT) has been widely adopted for the treatment of anal cancer (AC), the added contour complexity poses potential risks. This study investigates the impact of contour variation on tumour control probability (TCP) when using IMRT for AC. Methods: Nine Australian centres contoured a single computed tomography dataset of a patient with AC. The same optimised template-based IMRT planning protocol was applied to each contour set to generate nine representative treatment plans and their corresponding dose volume histograms. A geometric analysis was performed on all contours. The TCP was calculated for each plan using the linear …

Static Force Dependency Of Bone Conduction Transducer As Sensory Feedback For Stump-Socket Based Prosthesis, Raphael Mayer, Alireza Mohammadi, Gursel Alici, Peter Choong, Denny Oetomo

Faculty of Engineering and Information Sciences - Papers: Part B

The dependency of a novel sensory feedback for stump-socket based prosthesis on the static force is presented using a bone conduction transducer as feedback source. The stimulation was induced onto the bony landmarks of the elbow, specifically the Ulna and presented in an interval halving method. The perception threshold in the range of tactile and auditory perception at three different force levels has been tested. The inter subject variability is bigger than the intra subject variation. The small static force variation suggests a similar approach as in bone conduction hearing aids and therefore a static force bigger than 6N should …

Quality Evaluation Tests For Tensile Strength Of Reactive Powder Concrete, Hussamaldeen Goaiz, Tao Yu, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

This study presents a comparison between different testing procedures to determine the tensile strength of reactive powder concrete (RPC). The tensile strength test methods include a direct tensile test and two indirect tensile tests, the splitting test and the double punch test (DPT). In this study, the RPC was designed to obtain a nominal compressive strength of 100 MPa at the age of 28 days. Macro steel fibers were used to reinforce the RPC by volumetric percentages of 0, 1, 2, and 3%. Mechanical properties of RPC were obtained at 28 days such as compressive, tensile, and flexural strengths; compressive …

A Modified Black-Scholes Pricing Formula For European Options With Bounded Underlying Prices, Song-Ping Zhu, Xinjiang He

Faculty of Engineering and Information Sciences - Papers: Part B

In this paper, a modified Black-Scholes (B-S) model is proposed, based on a revised assumption that the range of the underlying price varies within a finite zone, rather than being allowed to vary in a semi-infinite zone as presented in the classical B-S theory. This is motivated by the fact that the underlying price of any option can never reach infinity in reality; a trader may use our new formula to adjust the option price that he/she is willing to long or short. To develop this modified option pricing formula, we assume that a trader has a view on the …

Modeling And Experimental Evaluation Of Bending Behavior Of Soft Pneumatic Actuators Made Of Discrete Actuation Chambers, Gursel Alici, Taylor Canty, Rahim Mutlu, Weiping Hu, Vitor Sencadas

Faculty of Engineering and Information Sciences - Papers: Part B

In this article, we have established an analytical model to estimate the quasi-static bending displacement (i.e., angle) of the pneumatic actuators made of two different elastomeric silicones (Elastosil M4601 with a bulk modulus of elasticity of 262 kPa and Translucent Soft silicone with a bulk modulus of elasticity of 48 kPa - both experimentally determined) and of discrete chambers, partially separated from each other with a gap in between the chambers to increase the magnitude of their bending angle. The numerical bending angle results from the proposed gray-box model, and the corresponding experimental results match well that the model is …

Combined Message Passing Based Sbl With Dirichlet Process Prior For Sparse Signal Recovery With Multiple Measurement Vectors, Zhengdao Yuan, Chuanzong Zhang, Qinghua Guo, Zhongyong Wang, Xinhua Lu, Sheng Wu

Faculty of Engineering and Information Sciences - Papers: Part B

This paper concerns the problem of sparse signal recovery with multiple measurement vectors, where the sparse signal vectors share multiple supports (i.e., the signal vectors can be clustered and the vectors in a cluster share a common support) and the prior knowledge on the supports of the vectors is unknown. This problem can be solved using sparse Bayesian learning (SBL) with Dirichlet process (DP) as hyper-prior, which is named DP-SBL in this paper. This work aims to design efficient inference algorithms. The variational inference for DP mixtures, in particular mean field (MF) inference, has been studied, and applying it to …

Delay-Dependent Fault-Tolerant Shape Control For Stochastic Distribution Systems, Yu Cheng, Long Chen, Tao Li, Haiping Du

Faculty of Engineering and Information Sciences - Papers: Part B

A new adaptive delay-dependent fault-tolerant shape control strategy is proposed for the stochastic distribution system with time-delay, which can effectively make the output probability density function (PDF) track a given target distribution. In this framework, firstly, a system model based on PDF with the actuator failure is constructed. And then, an adaptive delay-dependent fault-tolerant controller, which include a normal controller and an adaptive compensation controller is designed. The normal controller can track the given output distribution with an optimized performance index when there is no actuator fault, and the adaptive compensation controller can reduce the negative effects caused by the …

Design Of A Single-Layer Microchannel For Continuous Sheathless Single-Stream Particle Inertial Focusing, Yan Zhang, Jun Zhang, Fei Tang, Weihua Li, Xiaohao Wang

Faculty of Engineering and Information Sciences - Papers: Part B

High-throughput, high-precision single-stream focusing of microparticles has a potentially wide range of applications in biochemical analysis and clinical diagnosis. In this work, we develop a sheathless three-dimensional (3D) particle-focusing method in a single-layer microchannel. This novel microchannel consists of periodic high-aspect-ratio curved channels and straight channels. The proposed method takes advantage of both the curved channels, which induce Dean flow to promote particle migration, and straight channels, which suppress the remaining stirring effects of Dean flow to stabilize the achieved particle focusing. The 3D particle focusing is demonstrated experimentally, and the mechanism is analyzed theoretically. The effects of flow rate, …

Sensor-Enabled Activity Class Recognition In Preschoolers: Hip Versus Wrist Data, Stewart Trost, Dylan P. Cliff, Matthew Ahmadi, Tuc Nguyen, M. Hagenbuchner

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.

Multizone Soundfield Reproduction With Privacy- And Quality-Based Speech Masking Filters, Jacob Donley, Christian H. Ritz, W Kleijn

Faculty of Engineering and Information Sciences - Papers: Part B

Reproducing zones of personal sound is a challenging signal processing problem which has garnered considerable research interest in recent years. We introduce in this work an extended method to multizone soundfield reproduction which overcomes issues with speech privacy and quality. Measures of Speech Intelligibility Contrast (SIC) and speech quality are used as cost functions in an optimisation of speech privacy and quality. Novel spatial and (temporal) frequency domain speech masker filter designs are proposed to accompany the optimisation process. Spatial masking filters are designed using multizone soundfield algorithms which are dependent on the target speech multizone reproduction. Combinations of estimates …

A New Concentration Detection System For Sf6/N2 Mixture Gas In Extra/Ultra High Voltage Power Transmission Systems, Baojun Qu, Qingxin Yang, Yongjian Li, Reza Malekian, Zhixiong Li

Faculty of Engineering and Information Sciences - Papers: Part B

This paper develops a new detection system, for the first time, to detect the gas concentrations of the SF6/N2 mixture in extra/ultra-high voltage power transmission systems. The concentrations of SF6 and N2 are calculated from the thermal conductivity function of the mixture gas. The main contribution of this work is that a specially-designed thermostatic chamber with adaptive temperature controller is developed to ensure constant pressure of the gas flowed through the thermal conductivity sensor. Another contribution is the combination of multiple sensors (e.g. humidity and electrochemical sensors), which enables the detector to address the penetration effects of H2O and O2 …

Changes In Gait And Plantar Foot Loading Upon Using Vibrotactile Wearable Biofeedback System In Patients With Stroke, Christina Ma, Yong-Ping Zheng, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part B

Background: Patients with stroke walk with excessive foot inversion at the affected side, which may disturb their balance and gait. Objectives: This study aimed to investigate the effects of instant biofeedback of plantar force at the medial and lateral forefoot regions on gait and plantar foot loading in patients with stroke. Methods: A total of eight patients with hemiplegic stroke, who had flexible rearfoot varus deformity at the affected side, participated in this study. A vibrotactile biofeedback system was developed and evaluated. It analyzed forces at the medial and lateral forefeet, and instantly provided vibration clues when the plantar force …

Assessing The Integration Of Forward Osmosis And Anaerobic Digestion For Simultaneous Wastewater Treatment And Resource Recovery, Ashley Ansari, Faisal I. Hai, William E. Price, Hao H. Ngo, Wenshan Guo, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part B

This study assessed the performance and key challenges associated with the integration of forward osmosis (FO) and anaerobic digestion for wastewater treatment and resource recovery. Using a thin film composite polyamide FO membrane, maximising the pre-concentration factor (i.e. system water recovery) resulted in the enrichment of organics and salinity in wastewater. Biomethane potential evaluation indicated that methane production increased correspondingly with the FO pre-concentration factor due to the organic retention in the feed solution. At 90% water recovery, about 10% more methane was produced when using NaOAc compared with NaCl because of the contribution of biodegradable reverse NaOAc flux. No …