Engineering Commons^™

Encoding And Communicating Navigable Speech Soundfields, Xiguang Zheng, Christian H. Ritz, Jiangtao Xi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes a system for encoding and communicating navigable speech soundfields for applications such as immersive audio/visual conferencing, audio surveillance of large spaces and free viewpoint television. The system relies on recording speech soundfields using compact co-incident microphone arrays that are then processed to identify sources and their spatial location using the well-known assumption that speech signals are sparse in the time-frequency domain. A low-delay Direction of Arrival (DOA)-based frequency domain sound source separation approach is proposed that requires only 250 ms of speech signal. Joint compression is achieved through a previously proposed perceptual analysis-by-synthesis spatial audio coding scheme …

High Intrinsic Sensitivity Etched Polymer Fiber Bragg Grating Pair For Simultaneous Strain And Temperature Measurements, Kishore Bhowmik, Gang-Ding Peng, Yanhua Luo, Eliathamby Ambikairajah, Vedran Lovric, William R. Walsh, Ginu Rajan

Faculty of Engineering and Information Sciences - Papers: Part A

A sensing configuration for simultaneous measurement of strain and temperature with enhanced intrinsic sensitivity based on a fiber Bragg grating (FBG) pair with one grating inscribed in the etched and the other in unetched polymer fiber region is demonstrated. A poly (methyl methacrylate) based single-mode polymer fiber is etched to different diameters, and it is observed that etching can lead to change in the material properties of the fiber, such as Young's modulus and thermal expansion coefficient, which can play a vital role in improving its intrinsic sensing capabilities. Thus, exploiting the different strain and temperature sensitivities exhibited by etched …

Nonlocal Transistor Based On Pure Crossed Andreev Reflection In A Euo-Graphene/Superconductor Hybrid Structure, Yee Sin Ang, Lawrence Ang, C Zhang, Zhongshui Ma

Faculty of Engineering and Information Sciences - Papers: Part A

We study the interband transport in a superconducting device composed of graphene with EuO-induced exchange interaction. We show that pure crossed Andreev reflection can be generated exclusively without the parasitic local Andreev reflection and elastic cotunnelling over a wide range of bias and Fermi levels in an EuO-graphene/superconductor/EuO-graphene device. The pure nonlocal conductance exhibits rapid on-off switching and oscillatory behavior when the Fermi levels in the normal and the superconducting leads are varied. The oscillation reflects the quasiparticle propagation in the superconducting lead and can be used as a tool to probe the subgap quasiparticle mode in superconducting graphene, which …

Performance Of High Strength Concrete Columns Reinforced With Hybrid Steel Fiber Under Different Loading Conditions, Emdad K. Z Balanji, M Neaz Sheikh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

The strength and ductility of high strength concrete columns improve with the addition of steel fiber. This paper reports the behavior of circular High Strength Concrete (HSC) columns reinforced with Hybrid Steel Fibers (HSF) under different loading conditions. In this study, HSF consisted of a combination of macro steel fibers and micro steel fibers. A total of eight circular specimens of 205 mm diameter and 800 mm height were cast and tested. All specimens were reinforced with same amount of steel reinforcements. The specimens were divided into two groups of four specimens. Group RC (reference group) contained no steel fibers. …

An Alternative Form Used To Calibrate The Heston Option Pricing Model, Xin-Jiang He, Song-Ping Zhu

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents an alternative form of the Heston model that preserves an essential advantage of the Heston model, its analytic tractability, by imposing the necessary and sufficient conditions for the existence of a solution in affine form, while it is in a different form so that it offers certain advantages in parameter determination. To demonstrate this, we conducted some empirical studies, exploring if this new form does have certain advantages over the original version under certain market conditions.

Spatial And Temporal Antarctic Ice Sheet Mass Trends, Glacio-Isostatic Adjustment, And Surface Processes From A Joint Inversion Of Satellite Altimeter, Gravity, And Gps Data, Alba Martín-Español, Andrew Zammit-Mangion, Peter J. Clarke, Thomas Flament, Veit Helm, Matt A. King, Scott B. Luthcke, Elizabeth Petrie, Frederique Rémy, Nana Schön, Bert Wouters, Jonathan Bamber

Faculty of Engineering and Information Sciences - Papers: Part A

The Authors. We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic-corrected GPS data for the period 2003-2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time-invariant solution for glacio-isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003-2013, Antarctica has been losing mass at a rate of -84 ± 22 Gt yr-1, with a sustained negative mean trend of dynamic imbalance of -111 ± 13 Gt yr-1. West Antarctica is the largest contributor with -112 …

Bring Your Own Device: An Overview Of Risk Assessment, Robert Ogie

Faculty of Engineering and Information Sciences - Papers: Part A

As organizations constantly strive to improve strategies for ICT management, one of the major challenges they must tackle is bring your own device (BYOD). BYOD is a term that collectively refers to the related technologies, concepts, and policies in which employees are allowed to access internal corporate IT resources, such as databases and applications, using their personal mobile devices like smartphones, laptop computers, and tablet PCs [1]. It is a side effect of the consumerization of IT, a term used to describe the growing tendency of the new information technologies to emerge first in the consumer market and then spread …

Presenting Traveller Preference Heterogeneity In The Context Of Agency Theory: Understanding And Minimising The Agency Problem, Ahm Mehbub Anwar

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper agency theory has been used to interpret traveller preference heterogeneity in mode choice to understand agency problems. An agency problem is defined as a principal’s dissatisfaction with the outcome of an agent’s performance. Sydney statistical division travellers are considered as the principal and Transport for NSW (TfNSW) is treated as the agent. An agent performs the tasks that are delegated by the principal and thus a metaphoric contract is developed between them and travellers, for instance, show their satisfaction with the reliability and comfort of the transport service. TfNSW is expected to satisfy travellers’ desired services. Therefore, …

On The Accuracy Of Dose Prediction Near Metal Fixation Devices For Spine Sbrt, Zhangkai J. Cheng, Regina M. Bromley, Bradley M. Oborn, Martin Carolan, Jeremy T Booth

Faculty of Engineering and Information Sciences - Papers: Part A

The metallic fixations used in surgical procedures to support the spine mechanically usually consist of high-density materials. Radiation therapy to palliate spinal cord compression can include prophylactic inclusion of potential tumor around the site of such fixation devices. Determination of the correct density and shape of the spine fixation device has a direct effect on the dose calculation of the radiation field. Even with the application of modern computed tomography (CT), under- or overestimation of dose, both immediately next to the device and in the surrounding tissues, can occur due to inaccuracies in the dose prediction algorithm. In this study, …

Radar Imaging Of Stationary Indoor Targets Using Joint Low-Rank And Sparsity Constraints, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces a joint low-rank and sparsity-based model to address the problem of wall-clutter mitigation in compressed through-the-wall radar imaging. The proposed model is motivated by two observations that wall reflections reside in a low-rank subspace, and target signals tend to be sparse. In the proposed approach, the task of segregating target returns from wall reflections is formulated as a joint low-rank and sparsity constrained optimization problem. Here, the low rank constraint is imposed on the wall component and the sparsity constraint is used to model the target component. An iterative soft thresholding algorithm is developed to estimate a …

Variational Inference For Infinite Mixtures Of Sparse Gaussian Processes Through Kl-Correction, Thi Nhat Anh Nguyen, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Engineering and Information Sciences - Papers: Part A

We propose a new approximation method for Gaussian process (GP) regression based on the mixture of experts structure and variational inference. Our model is essentially an infinite mixture model in which each component is composed of a Gaussian distribution over the input space, and a Gaussian process expert over the output space. Each expert is a sparse GP model augmented with its own set of inducing points. Variational inference is made feasible by assuming that the training outputs are independent given the inducing points. In previous works on variational mixture of GP experts, the inducing points are selected through a …

Organ Doses From Hepatic Radioembolization With 90y, 153sm, 166ho And 177lu: A Monte Carlo Simulation Study Using Geant4, N A A Hashikin, C H Y Yeong, Susanna Guatelli, B J J Abdullah, K H. Ng, Alessandra Malaroda, Anatoly B. Rosenfeld, A C. Perkins

Faculty of Engineering and Information Sciences - Papers: Part A

90Y-radioembolization is a palliative treatment for liver cancer. 90Y decays via beta emission, making imaging difficult due to absence of gamma radiation. Since post-procedure imaging is crucial, several theranostic radionuclides have been explored as alternatives. However, exposures to gamma radiation throughout the treatment caused concern for the organs near the liver. Geant4 Monte Carlo simulation using MIRD Pamphlet 5 reference phantom was carried out. A spherical tumour with 4.3cm radius was modelled within the liver. 1.82GBq of 90Y sources were isotropically distributed within the tumour, with no extrahepatic shunting. The simulation was repeated with 153Sm, 166Ho and 177Lu. The estimated …

Cartan Subalgebras In C*-Algebras Of Hausdorff Étale Groupoids, Jonathan H. Brown, Gabriel Nagy, Sarah Reznikoff, Aidan Sims, Dana P. Williams

Faculty of Engineering and Information Sciences - Papers: Part A

The reduced C*-algebra of the interior of the isotropy in any Hausdorff étale groupoid G embeds as a C*-subalgebra M of the reduced C*-algebra of G. We prove that the set of pure states of M with unique extension is dense, and deduce that any representation of the reduced C*-algebra of G that is injective on M is faithful. We prove that there is a conditional expectation from the reduced C*-algebra of G onto M if and only if the interior of the isotropy in G is closed. Using this, we prove that when the interior of the isotropy is …

Finite Maturity Margin Call Stock Loans, Xiaoping Lu, Endah Putri

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we formulate margin call stock loans in finite maturity as American down-and-out calls with rebate and time-dependent strike. The option problem is solved semi-analytically based on the approach in Zhu (2006). An explicit equation for optimal exit price and a pricing formula for loan value are obtained in Laplace space. Final results are obtained by numerical inversion. Examples are provided to show the dependency of the optimal exit price and margin call stock loan value on various parameters.

A Novel Queue Management Policy For Delay-Tolerant Networks, Saeid Iranmanesh

Faculty of Engineering and Information Sciences - Papers: Part A

Delay-tolerant networks (DTNs) have attracted increasing attention from governments, academia and industries in recent years. They are designed to provide a communication channel that exploits the inherent mobility of trams, buses and cars. However, the resulting highly dynamic network suffers from frequent disconnections, thereby making node-to-node communications extremely challenging. Researchers have thus proposed many routing/forwarding strategies in order to achieve high delivery ratios and/or low latencies and/or low overheads. Their main idea is to have nodes store and carry information bundles until a forwarding opportunity arises. This, however, creates the following problems. Nodes may have short contacts and/or insufficient buffer …

Driver Alerting System Using Range Estimation Of Electric Vehicles In Real Time Under Dynamically Varying Environmental Conditions, Vincent R. Tannahill, Kashem M. Muttaqi, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

As the technology supporting electric vehicles (EVs) is rapidly progressing and the cost of EV components is reducing, EVs are becoming more feasible for use in Australia and in many countries around the world. However, the public perception of EVs and their perceived limitations result in a slow uptake of the technology, partially because of the uncertainty regarding the ability of an EV to meet the driving needs of the general population. Range anxiety is a particular concern with drivers having fear of being stranded by a depleted EV battery. This study explores means of reducing range anxiety by taking …

Biosolids Reduction By The Oxic-Settling-Anoxic Process: Impact Of Sludge Interchange Rate, Galilee U. Semblante, Faisal I. Hai, Heriberto A. Bustamante, Nelly Guevara, William E. Price, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

The impact of sludge interchange rate (SIR) on sludge reduction by oxic-settling-anoxic (OSA) process was investigated. The sludge yield of an OSA system (a sequencing batch reactor, SBR, integrated with external anoxic reactors) was compared to that of a control (an SBR attached to a single-pass aerobic digester). SIR (%) is the percentage by volume of sludge returned from the external reactor into the main bioreactor of the OSA, and was varied from 0-22%. OSA achieved greater sludge reduction when fed with unsettled sewage (sCOD=113 mg/L) rather than settled sewage (sCOD=60 mg/L). The SIR of 11% resulted in the highest …

Axial And Flexural Behavior Of Unreinforced And Frp Bar Reinforced Circular Concrete Filled Frp Tube Columns, Muhammad N. S Hadi, Qasim Khan, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part A

Fiber Reinforced Polymer (FRP) composites have emerged as a viable alternative of steel reinforcement due to higher ultimate tensile strength to weight ratio and corrosion resistance of FRP composites. Concrete Filled Fiber Reinforced Polymer Tube (CFFT) technique for new column construction has attracted significant research attention. This paper investigated the axial and flexural behavior of concrete filled Carbon FRP (CFRP) tube columns with and without CFRP bar and concrete filled Glass FRP (GFRP) tube columns with and without GFRP bar. The test results of 16 circular CFFT and four steel Reinforced Concrete (RC) specimens of 203-205 mm diameter and 800-812 …

Continuous Adsorption And Biotransformation Of Micropollutants By Granular Activated Carbon-Bound Laccase In A Packed-Bed Enzyme Reactor, Ngoc Luong Nguyen, Faisal I. Hai, Anthony Dosseto, Christopher Richardson, William E. Price, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

Laccase was immobilized on granular activated carbon (GAC) and the resulting GAC-bound laccase was used to degrade four micropollutants in a packed-bed column. Compared to the free enzyme, the immobilized laccase showed high residual activities over a broad range of pH and temperature. The GAC-bound laccase efficiently removed four micropollutants, namely, sulfamethoxazole, carbamazepine, diclofenac and bisphenol A, commonly detected in raw wastewater and wastewater-impacted water sources. Mass balance analysis showed that these micropollutants were enzymatically degraded following adsorption onto GAC. Higher degradation efficiency of micropollutants by the immobilized compared to free laccase was possibly due to better electron transfer between …

Analysis Of Bacterial Diversity In Two Oil Blocks From Two Low-Permeability Reservoirs With High Salinities, Meng Xiao, Shan Shan Sun, Zhong Zhi Zhang, Junming Wang, Long Wei Qiu, Hua Yang Sun, Zhaozheng Song, Beiyu Zhang, De Li Gao, Guangqing Zhang, Wei Min Wu

Faculty of Engineering and Information Sciences - Papers: Part A

The community diversities of two oil reservoirs with low permeability of 1.81 x 10 '3 and 2.29 x 10 '3 1/4m 2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher …

Effect Of Gaseous Hydrogen Charging On The Tensile Properties Of Standard And Medium Mn X70 Pipeline Steels, Daniel Hejazi, Andrzej Calka, Druce P. Dunne, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The tensile properties of two X70 steels with high (1.14 wt-%) and medium (0.5 wt-%) Mn contents have been investigated by testing at 25°C of tubular specimens charged with an internal gas pressure of 10 MPa of hydrogen or argon. The hydrogen-charged samples were additionally tested at 50 and 100°C. Tensile testing showed that the equiaxed ferrite-pearlite microstructure of higher Mn steel was most sensitive to hydrogen embrittlement and that the banded ferrite- pearlite microstructure of the higher Mn strip was more susceptible to hydrogen embrittlement than the medium Mn strip. The more highly banded ferrite-pearlite microstructure in the higher …

Coke Degradation Under Simulated Blast Furnace Conditions, Xing Xing, Harold P. Rogers, Guangqing Zhang, Kim Hockings, Paul Zulli, Oleg Ostrovski

Faculty of Engineering and Information Sciences - Papers: Part A

Three metallurgical cokes made from coking coals over a significant range in rank were subjected to treatment with blast furnace-like gas composition-temperature profile to 1 673 K, annealing under N2 to 2 273 K and gasification with subsequent annealing at 1 873 and 2 273 K. The degradation of cokes after reaction and annealing was characterised using I-drum tumbling, tensile testing, ultra-micro indentation and X-ray diffraction. Both gasification and annealing decreased the mechanical strength of coke. Compared with annealing at 1 673 K, gasification at same temperature caused larger degradation for all three cokes, and the effect was more significant …

Confined Sno2 Quantum-Dot Clusters In Graphene Sheets As High-Performance Anodes For Lithium-Ion Batteries, Chengling Zhu, Shenmin Zhu, Kai Zhang, Zeyu Hui, Hui Pan, Zhixin Chen, Yao Li, Di Zhang, Dawei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO₂-based anode. The novel structure consists of mesoporous clusters of SnO₂ quantum dots (SnO₂ QDs), which are wrapped with reduced graphene oxide (RGO) sheets. The mesopores inside the clusters provide enough room for the expansion and contraction of SnO₂ QDs during charge/discharge process while the integral structure …

Encapsulation Of Fe3o4 Nanoparticles Into N, S Co-Doped Graphene Sheets With Greatly Enhanced Electrochemical Performance, Zunxian Yang, Kun Qian, Jun Lv, Wenhuan Yan, Jiahui Liu, Jingwei Ai, Yuxiang Zhang, Tailiang Guo, Xiongtu Zhou, Sheng Xu, Zaiping Guo

Faculty of Engineering and Information Sciences - Papers: Part A

Particular N, S co-doped graphene/Fe₃O₄ hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe₃O₄ nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe₃O₄ composite electrode exhibits a high initial reversible capacity …

Development And Performance Evaluation Of A Liquid Desiccant Air Conditioning System With Hybrid Electrodialysis And Thermal Regeneration, Yi Guo, Zhenjun Ma, Ali Hussein Al-Jubainawi, Paul Cooper, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

Liquid desiccant air conditioning (LDAC) systems have gained increasing attention due to the improved energy performance and reduced environmental impacts. This paper presents an LDAC system using electrodialysis (ED) as well as low grade heat generated from a hybrid photovoltaic thermal and evacuated tube (PVT-ET) collector for liquid desiccant regeneration. As ED regenerator is a key component in the proposed system, a modified mathematical model is used to simulate the mass transfer of the ED stack. The performance of the model was validated using the experimental data generated based on a lab-scale experimental setup. It is shown that the model …

A Simple Proof Of Euler's Continued Fraction Of E^{1/M}, Joseph Tonien

Faculty of Engineering and Information Sciences - Papers: Part A

A continued fraction is an expression of the form

f₀+ g₀

f₁+g₁

f₂+g₂

and we will denote it by the notation [f₀, (g₀, f₁), (g₁, f₂), (g₂, f₃), … ]. If the numerators g_i are all equal to 1 then we will use a shorter notation [f₀, f₁, f₂, f₃, … ]. A simple continued fraction is a continued fraction with all the …

Effects Of Salinity Build-Up On The Performance Of An Anaerobic Membrane Bioreactor Regarding Basic Water Quality Parameters And Removal Of Trace Organic Contaminants, Xiaoye Song, James A. Mcdonald, William E. Price, Stuart J. Khan, Faisal I. Hai, Hao H. Ngo, Wenshan Guo, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

The effects of elevated inorganic salt concentration on anaerobic membrane bioreactor (AnMBR) treatment regarding basic biological performance and trace organic contaminant (TrOC) removal were investigated. A set of 33 TrOCs were selected to represent pharmaceuticals, steroids, and pesticides in municipal wastewater. Results show potential adverse effects of increase in the bioreactor salinity to 15 g/L (as NaCl) on the performance of AnMBR with respect to chemical oxygen demand removal, biogas production, and the removal of most hydrophilic TrOCs. Furthermore, a decrease in biomass production was observed as salinity in the bioreactor increased. The removal of most hydrophobic TrOCs was high …

Statistical Bias And Variance For The Regularized Inverse Problem: Application To Space-Based Atmospheric Co2 Retrievals, Noel A. Cressie, R Wang, Michael M. Smyth, Charles E. Miller

Faculty of Engineering and Information Sciences - Papers: Part A

Remote sensing of the atmosphere is typically achieved through measurements that are high-resolution radiance spectra. In this article, our goal is to characterize the first-moment and second-moment properties of the errors obtained when solving the regularized inverse problem associated with space-based atmospheric CO2 retrievals, specifically for the dry air mole fraction of CO2 in a column of the atmosphere. The problem of estimating (or retrieving) state variables is usually ill posed, leading to a solution based on regularization that is often called Optimal Estimation (OE). The difference between the estimated state and the true state is defined to be the …

Student Rules: Exploring Patterns Of Students' Computer-Efficacy And Engagement With Digital Technologies In Learning, Sarah Katherine Howard, Jun Ma, Jie Yang

Faculty of Engineering and Information Sciences - Papers: Part A

Teachers' beliefs about students' engagement in and knowledge of digital technologies will affect technologically integrated learning designs. Over the past few decades, teachers have tended to feel that students were confident and engaged users of digital technologies, but there is a growing body of research challenging this assumption. Given this disparity, it is necessary to examine students' confidence and engagement using digital technologies to understand how differences may affect experiences in technologically integrated learning. However, the complexity of teaching and learning can make it difficult to isolate and study multiple factors and their effects. This paper proposes the use of …

Ambient Controlled Synthesis Of Advanced Core-Shell Plasmonic Ag@Zno Photocatalysts, Jinyan Xiong, Qiao Sun, Jun Chen, Zhen Li, S X. Dou

Faculty of Engineering and Information Sciences - Papers: Part A

Plasmonic Ag@ZnO core-shell hybrids, including hetero-nanowires and hetero-nanoparticles, have been synthesized at room temperature for application in photocatalysis. The morphology, size, crystal structure, and composition of the products were investigated by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy. It was found the concentration of Zn(NO3)2·6H2O and the amount of water play crucial roles in the formation of Ag@ZnO core-shell hybrids. The resultant Ag@ZnO core-shell hybrids exhibit much higher photocatalytic activity and stability towards degradation of organic contaminants than pure ZnO nanocrystals under solar light irradiation. The one-dimensional (1D) core-shell hetero-nanowires prepared under optimal conditions …