Social and Behavioral Sciences Commons^™

Numerical Comparison Between Berkovich And Conical Nano-Indentations: Mechanical Behaviour And Micro-Texture Evolution, Mao Liu, Cheng Lu, A Kiet Tieu, Hailiang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

A crystal plasticity finite element method (CPFEM) model has been developed to investigate the influence of indenter geometry on the mechanical behaviour and micro-texture evolution during nano-indentation of single crystal aluminium. The developed model has been validated by comparison with experimental observations. The numerical results show that indenter geometry influences the load-indentation depth curve, hardness and elastic modulus significantly. The surface profile, equivalent plastic strain distribution and micro-texture evolution during nano-indentation have been analysed in detail.

Making A Hydrophoretic Focuser Tunable Using A Diaphragm, Sheng Yan, Jun Zhang, Huaying Chen, Gursel Alici, Haiping Du, Yonggang Zhu, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

Microfluidic diagnostic devices often require handling particles or cells with different sizes. In this investigation, a tunable hydrophoretic device was developed which consists of a polydimethylsiloxane (PDMS) slab with hydrophoretic channel, a PDMS diaphragm with pressure channel, and a glass slide. The height of the hydrophoretic channel can be tuned simply and reliably by deforming the elastomeric diaphragm with pressure applied on the pressure channel. This operation allows the device to have a large operating range where different particles and complex biological samples can be processed. The focusing performance of this device was tested using blood cells that varied in …

Dynamic Adjustment Of Oltc Parameters Using Voltage Sensitivity While Utilizing Dg For Volt/Var Support, Dothinka Ranamuka Rallage, Ashish Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage regulation in medium voltage (MV) distribution systems is still widely performed with the aid of substation on-load tap changer (OLTC). An OLTC can be operated with or without enacting the line drop compensation (LDC) module embedded in the OLTC control. However, in case of distribution systems with higher penetration of renewable and distributed generation (DG), it is well known that the DG reverse power flow can increase the number of OLTC tap operations under certain system conditions. On the other hand, voltage correction by DG is one of the promising concepts highly regarded by the researchers and engineers. In …

Mitigating Tap-Changer Limit Cycles In Modern Electricity Networks Embedded With Local Generation Units, Dothinka Ranamuka Rallage, Ashish Agalgaonkar, Kashem M. Muttaqi, Md Jan E Alam

Faculty of Engineering and Information Sciences - Papers: Part A

Cascaded on-load tap changers (OLTC) are widely used for coarse voltage control in electric power systems. There could be an interaction between load dynamics and OLTC control under certain system operating conditions which may lead to OLTC limit cycle phenomena thereby resulting into long term voltage oscillations in the system. In the recent years, renewable and non-renewable local generation units have been getting interconnected in modern power systems. The existence of OLTC limit cycles in the presence of local generation units has not been addressed thoroughly in the literature. In this paper, the OLTC limit cycle phenomena, which can occur …

Influence Of Isothermal Treatment On Mns And Hot Ductility In Low Carbon, Low Mn Steels, Kristin R. Carpenter, Chris Killmore, Rian J. Dippenaar

Faculty of Engineering and Information Sciences - Papers: Part A

Hot ductility tests were used to determine the hot-cracking susceptibility of two low-carbon, low Mn/S ratio steels and compared with a higher-carbon plain C-Mn steel and a low C, high Mn/S ratio steel. Specimens were solution treated at 1623 K (1350 °C) or in situ melted before cooling at 100 K/min to various testing temperatures and strained at 7.5 x 10-4 s -1, using a Gleeble 3500 Thermomechanical Simulator. The low C, low Mn/S steels showed embrittlement from 1073 K to 1323 K (800 °C to 1050 °C) because of precipitation of MnS at the austenite grain boundaries combined with …

Intelligent Control Of Electroactive Polymer Actuators Based On Fuzzy And Neurofuzzy Methodologies, Christopher M. Druitt, Gursel Alici

Faculty of Engineering and Information Sciences - Papers: Part A

Conjugated conducting polymer actuators, especially those based on polypyrrole (PPy), possess enormous potential for the creation of biomimetic devices, single-cell manipulators, numerous biomedical applications as well as robotics and prosthetics. This is due to their low actuation voltage, ability to operate at the macro- or microscale, large force-to-weight ratio, biocompatibility, low cost and their operation in aqueous and nonaqueous environments. This paper experimentally investigates the potential of intelligent control methodologies to improve the positional accuracy and response speed of trilayer PPy actuators. Two intelligent control techniques were designed and implemented - fuzzy logic PD+I control and neurofuzzy adaptive neural fuzzy …

Feasibility Study Of Low Force Robotic Friction Stir Process And Its Effect On Cavitation Erosion And Electrochemical Corrosion For Ni Al Bronze Alloys, Azman Ahmad, Huijun Li, Zengxi Pan, Dominic Cuiuri, Stephen Van Duin, Nathan Larkin, Joseph Polden, Nathan Lane

Faculty of Engineering and Information Sciences - Papers: Part A

Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the …

Smart Home System: Integration Of Energy Facilities And Environmental Factors, Weiliang Zhao, Lan Ding, Paul Cooper, Pascal Perez, Duane A. Robinson

Faculty of Engineering and Information Sciences - Papers: Part A

This paper concerns the soft-in soft-out detection in a coded communication system, where the transmitted symbols are discrete valued, and the exact a posteriori probability (APP) detection often involves prohibitive complexity. By using the properties of Gaussian functions, an approximate approach to the APP detection is devised with the idea that, in the computation of the APP of each symbol, the remaining symbols are distinguished based on their contributions to the APP of the concerned symbol, and the symbols with less contributions are approximated as (continuous) Gaussian variables [hence the name partial Gaussian approximation (PGA)] to reduce the computational complexity. …

Abnormally High Residual Dislocation Density In Pure Aluminum After Al/Ti/Al Laminate Annealing For Seven Days, Hailiang Yu, A Kiet Tieu, Cheng Lu, Charlie Kong

Faculty of Engineering and Information Sciences - Papers: Part A

We report an abnormally high residual dislocation density in aluminium in an Al/Ti/Al laminate annealed at 873 K for seven days. The residual dislocation density reaches 7.5 x 1014 m−2, higher than that in aluminum after severe plastic deformation processes such as accumulative roll bonding and high-pressure torsion. It is proposed that the high residual dislocation density may result from obstruction of the movement of TiAl3 nanoparticles by the grain boundary and Ti atoms conglomerating at vacancies distributed in the aluminium matrix at a high temperature for a sufficient time to allow a relatively stable crystal.

An Improved Genetic Algorithm For Cost-Effective Data-Intensive Service Composition, Lijuan Wang, Jun Shen, Junzhou Luo, Fang Dong

Faculty of Engineering and Information Sciences - Papers: Part A

The explosion of digital data and the dependence on data-intensive services have been recognized as the most significant characteristics of IT trends in the current decade. Designing workflow of data-intensive services requires data analysis from multiple sources to get required composite services. Composing such services requires effective transfer of large data. Thus many new challenges are posed to control the cost and revenue of the whole composition. This paper addresses the data-intensive service composition and presents an innovative data-intensive service selection algorithm based on a modified genetic algorithm. The performance of this new algorithm is also tested by simulations and …

Liner Ship Route Schedule Design With Port Time Windows, Shuaian Wang, Abdurahim Alharbi, Pamela Davy

Faculty of Engineering and Information Sciences - Papers: Part A

This paper examines a practical tactical liner ship route schedule design problem, which is the determination of the arrival and departure time at each port of call on the ship route. When designing the schedule, the availability of each port in a week, i.e., port time window, is incorporated. As a result, the designed schedule can be applied in practice without or with only minimum revisions. This problem is formulated as a mixed-integer nonlinear nonconvex optimization model. In view of the problem structure, an efficient holistic solution approach is proposed to obtain global optimal solution. The proposed solution method is …

Elastic Models For Nonlinear Response Of Rigid Passive Piles, Wei Dong Guo

Faculty of Engineering and Information Sciences - Papers: Part A

Recent study indicates that the response of rigid passive piles is dominated by elastic pile–soil interaction and may be estimated using theory for lateral piles. The difference lies in that passive piles normally are associated with a large scatter of the ratio of maximum bending moment over maximum shear force and induce a limiting pressure that is ~1/3 that on laterally loaded piles. This disparity prompts this study.

This paper proposes pressure-based pile–soil models and develops their associated solutions to capture response of rigid piles subjected to soil movement. The impact of soil movement was encapsulated into a power-law distributed …

Mixed Quadratic-Cubic Autocatalytic Reaction-Diffusion Equations: Semi-Analytical Solutions, Muteb Alharthi, Timothy Marchant, Mark Nelson

Faculty of Engineering and Information Sciences - Papers: Part A

Semi-analytical solutions for autocatalytic reactions with mixed quadratic and cubic terms are considered. The kinetic model is combined with diffusion and considered in a onedimensional reactor. The spatial structure of the reactant and autocatalyst concentrations are approximated by trial functions and averaging is used to obtain a lower-order ordinary differential equation model, as an approximation to the governing partial differential equations. This allows semi-analytical results to be obtained for the reaction–diffusion cell, using theoretical methods developed for ordinary differential equations. Singularity theory is used to investigate the static multiplicity of the system and obtain a parameter map, in which the …

Tensile Fracture Of Ultrafine Grained Aluminum 6061 Sheets By Asymmetric Cryorolling For Microforming, Hailiang Yu, A Kiet Tieu, Cheng Lu, Yanshan Lou, Xianghua Liu, Ajit R. Godbole, Charlie Kong

Faculty of Engineering and Information Sciences - Papers: Part A

The size effect on the mechanism of fracture in ultrafine grained sheets is an unsolved problem in microforming. This paper describes a tensile test carried out to study the fracture behavior and the shear fracture angles of both rolled and aged ultrafine grained aluminum 6061 sheets produced by asymmetric cryorolling. A scanning electron microscope was used to observe the fracture surface. The finite element method was used to simulate the tensile test using the uncoupled Cockcroft-Latham and Tresca criteria and the coupled Gurson-Tvergaard-Needleman damage criterion. It was found that the shear fracture angle decreases gradually from 90 degrees to 64 …

Mentoring A Health Technology Assessment Initiative In Kazakhstan, Sergei Muratov, David Hailey, Vicki Foerster, Bruce Brady, Don Juzwishin, Philip La Fleur, Jessie Mcgowan

Faculty of Engineering and Information Sciences - Papers: Part A

Objectives: The aim of this study was to assist in the development of a health technology assessment (HTA) program for the Ministry of Health (MOH) of the Republic of Kazakhstan.

Methods: Mentoring of an initial HTA program in Kazakhstan was provided by the Canadian Society for International Health (CSIH) by means of a partnership with the Kazakhstan MOH. HTA materials, courses, and one-on-one support for the preparation of a series of initial HTA reports by MOH HTA staff were provided by a seven-member CSIH team over a 2.5-year project.

Results: Guidance documents on HTA and institutional strengthening were prepared in …

Testing Model Transformation Programs Using Metamorphic Testing, Mingyue Jiang, Tsong Yueh Chen, Fei-Ching Kuo, Zhiquan Zhou, Zuohua Ding

Faculty of Engineering and Information Sciences - Papers: Part A

Model transformations are crucial for the success of Model Driven Engineering. Testing is a prevailing technique of verifying the correctness of model transformation programs. A major challenge in model transformation testing is the oracle problem, which refers to the difficulty or high cost in determining the correctness of the output models. Metamorphic Testing alleviates the oracle problem by making use of the relationships among the inputs and outputs of multiple executions of the target function. This paper investigates the effectiveness and feasibility of metamorphic testing in testing model transformation programs. Empirical results show that metamorphic testing is an effective testing …

A Probabilistic Analysis Of Human Influence On Recent Record Global Mean Temperature Changes, Phillip Kokic, Steven Crimp, Mark Howden

Faculty of Engineering and Information Sciences - Papers: Part A

December 2013 was the 346th consecutive month where global land and ocean average surface temperature exceeded the 20th century monthly average, with February 1985 the last time mean temperature fell below this value. Even given these and other extraordinary statistics, public acceptance of human induced climate change and confidence in the supporting science has declined since 2007. The degree of uncertainty as to whether observed climate changes are due to human activity or are part of natural systems fluctuations remains a major stumbling block to effective adaptation action and risk management. Previous approaches to attribute change include qualitative expert-assessment approaches …

Cloud Computing Technology: Reducing Carbon Footprint In Beef Supply Chain, Akshit Singh, Nishikant Mishra, Syed Imran Ali, Nagesh Shukla, Ravi Shankar

Faculty of Engineering and Information Sciences - Papers: Part A

Global warming is an alarming issue for the whole humanity. The manufacturing and food supply chains are contributing significantly to the large-scale carbon emissions. Beef supply chain is one of the segments of food industry having considerable carbon footprint throughout its supply chain. The major emissions are occurring at beef farms in the form of methane and nitrous oxide gases. The other carbon hotspots in beef supply chain are abattoir, processor, logistics and retailer. There is a huge amount of pressure from government authorities to all the business firms to cut down carbon emissions. The different stakeholders of beef supply …

An Approach To Ultra-Wideband Channel Calibration Using A Vector Network Analyser, Ahmed Moftah Ownalla Alshabo, David Stirling, Montserrat Ros, Peter J. Vial, Beata J. Wysocki, Tadeusz Wysocki

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, two calibration methods are investigated to determine the most suitable approach for ultra-wideband (UWB) communication channel measurements. The fi rst method is the through, open, short and match (TOSM) calibration technique. The second method is through, refl ection and load calibration technique. Presented experiment results show that the through, refl ection and load calibration process is more precise for calibration of coaxial cables and the UWB channel as clearly seen by increased magnitudes of the channel transfer function. It is also shown that the proposed through, refl ection and load technique leads to an improved larger measured …

Mean Field Variational Bayes For Continuous Sparse Signal Shrinkage: Pitfalls And Remedies, Sarah E. Neville, John Ormerod, M P. Wand

Faculty of Engineering and Information Sciences - Papers: Part A

We investigate mean field variational approximate Bayesian inference for models that use continuous distributions, Horseshoe. Negative-Exponential-Gamma and Generalized Double Pareto, for sparse signal shrinkage. Our principal finding is that the most natural, and simplest, mean field variational Bayes algorithm can perform quite poorly due to posterior dependence among auxiliary variables. More sophisticated algorithms, based on special functions, are shown to be superior. Continued fraction approximations via Lentz's Algorithm are developed to make the algorithms practical.

The Shrinking Figure Eight And Other Solitons For The Curve Diffusion Flow, Maureen Edwards, Alexander Gerhardt-Bourke, James A. Mccoy, Glen Wheeler, V. -M Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

In this article we investigate the dynamics of special solutions to the surface diffusion flow of idealised ribbons. This reduces to studying the curve diffusion flow for the profile curve of the ribbon. We provide: (1) a complete classification of stationary solutions; (2) qualitative results on shrinkers, translators, and rotators; and (3) an explicit parametrisation of a shrinking figure eight curve.

On Complete Target Coverage In Wireless Sensor Networks With Random Recharging Rates, Changlin Yang, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

A fundamental problem inWireless Sensor Networks (WSNs) is determining the minimum active time of a set of sensor nodes such that they monitor all targets for the maximum time. However, existing solutions do not consider random recharging rates and staled battery level information, resulting in an activation schedule that is not realizable by sensor nodes. Henceforth, we propose a Stochastic Programming (SP) based approach that considers random battery levels. Experimental results show our SP approach achieves 80% of the theoretically achievable coverage lifetime.

Experimental Study For The Influence Of Surface Characteristics On The Fringe Patterns, Yifan Wei, Jiangtao Xi, Yanguang Yu, Qinghua Guo, Yongkai Yin

Faculty of Engineering and Information Sciences - Papers: Part A

Fringe projection profilometry (FPP) has been widely used for three dimensional (3D) imaging and measurement. The fringe acquisition of FPP mainly depends on the diffuse light from the surface of objects, thus the characteristics of object surface have significant influence on phase calculation. One of the essential factors related to phase precision is modulation index, which has a direct relationship with the surface reflectivity. This paper presents a comparative study which focuses on the modulation index of different materials. The distribution of modulation index for different samples is statistical analyzed, which leads to the conclusion that the modulation index is …

On Globally Non-Trivial Almost-Commutative Manifolds, Jord Boeijink, Koen Van Den Dungen

Faculty of Engineering and Information Sciences - Papers: Part A

Within the framework of Connes’ noncommutative geometry, we define and study globally non-trivial (or topologically non-trivial) almost-commutative manifolds. In particular, we focus on those almost-commutative manifolds that lead to a description of a (classical) gauge theory on the underlying base manifold. Such an almost-commutative manifold is described in terms of a “principal module,” which we build from a principal fibre bundle and a finite spectral triple. We also define the purely algebraic notion of “gauge modules,” and show that this yields a proper subclass of the principal modules. We describe how a principal module leads to the description of a …

Influence Of Coal Particle Size On Coal Adsorption And Desorption Characteristics, Lei Zhang, Naj Aziz, Ting Ren, Jan Nemcik, Shihao Tu

Faculty of Engineering and Information Sciences - Papers: Part A

Accurate testing coal isotherm can play a significant role in the areas of coal seam gas drainage, outburst control, CO2 geo-sequestration, coalbed methane (CBM) and enhanced coalbed methane recovery (ECBM) etc. The effect of particle size on the CO2 and CH4 sorption capacity of bituminous coal from Illawarra, Australia was investigated at 35°C and at pressure up to 4 MPa. A unique indirect gravimetric apparatus was used to measure the gas adsorption and desorption isotherms of coal of different particle sizes ranging from around 150 urn to 16 mm. Langmuir model was used to analysis the experimental results of all …

Improving Privacy And Security In Decentralized Ciphertext-Policy Attribute-Based Encryption, Jinguang Han, Willy Susilo, Yi Mu, Jianying Zhou, Man Ho Au

Faculty of Engineering and Information Sciences - Papers: Part A

In previous privacy-preserving multi-authority attribute-based encryption (PPMA-ABE) schemes, a user can acquire secret keys from multiple authorities with them knowing his/her attributes and furthermore, a central authority is required. Notably, a user’s identity information can be extracted from his/her some sensitive attributes. Hence, existing PPMAABE schemes cannot fully protect users’ privacy as multiple authorities can collaborate to identify a user by collecting and analyzing his attributes. Moreover, ciphertext-policy ABE (CPABE) is a more efficient public-key encryption where the encryptor can select flexible access structures to encrypt messages. Therefore, a challenging and important work is to construct a PPMA-ABE scheme where …

Study On Micro Hydroforming Of Metals, Liang Luo, Zhengyi Jiang, Dongbin Wei, Xiaofeng He

Faculty of Engineering and Information Sciences - Papers: Part A

Micro hydroforming has an ability to manufacture complex 3D micro parts at a high production rate and has drawn increasing attentions. Brief understanding of macro hydroforming, for instance, deep drawing, is necessary to understand the principle of micro hydroforming. Then, special phenomena, such as size effects, occurred at micro scale are discussed and the related theories explaining these phenomena are introduced. Based on the similarities and differences between micro and macro hydroforming, experiments and simulation which consider the size effects are reviewed.

Weld-End Solidification Cracking In Pulsed-Tandem Gas Metal Arc Welding Of Naval Steels, Zoran Sterjovski, C Bayley, J Donato, Nathan Lane, D Lang

Faculty of Engineering and Information Sciences - Papers: Part A

Pulsed tandem gas metal arc welding (PT-GMAW) has the potential to increase productivity and minimize distortion in the fabrication of naval surface ship panels. In this study, the PT-GMAW process was used in pulse-pulse mode to butt joint weld 5-mm DH36,8-mm HSLA65, 9.5-mm 350WT, and 11-mm HSLA65 steel plate with ER70S-6 wire in order to assess its suitability as a replacement for submerged arc welding (SAW) and gas metal arc welding (GMAW) in panel lines of Australian naval shipyards. In the pulse-pulse mode, the wire feed rates for the leading and trailing welding wires are set independently and they alternately …

Investigation Of Ultrafine Grained Aa1050 Fabricated By Accumulative Roll Bonding, Lihong Su, Cheng Lu, Huijun Li, Guanyu Deng, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

Accumulative roll bonding (ARB) is an effective method to produce ultrafine-grained (UFG) sheet materials with high strength. In this work, fully annealed AA1050 sheet with an initial thickness of 1.5. mm was processed by ARB up to five cycles. The microstructure was examined by optical microscopy (OM) and transmission electron microscopy (TEM). The results revealed that ARB is a promising process for fabricating ultrafine grained structures in aluminium sheets and the average grain size after 5-cycle ARB reached approximately 300. nm. Meanwhile, a remarkable enhancement in the strength was achieved and the value was about three times the strength of …

Tribological Analysis Of Oxide Scales During Cooling Process Of Rolled Microalloyed Steel, Zhengyi Jiang, Xianglong Yu, Jingwei Zhao, Cunlong Zhou, Qingxue Huang, Guangzheng Luo, Kezhi Linghu

Faculty of Engineering and Information Sciences - Papers: Part A

The composition and phase transformation of oxide scale in cooling process (after hot rolling) of rolled microalloyed steels affect tribological features of rolled strip and downstream process, and the produced steel surface quality. In this study, physical simulation of surface roughness transfer during cooling process with consideration of ultra fast cooling (UFC) was carried out in Hille 100 experimental rolling mill, the obtained oxide scale was examined with SEM to show its surface and phase features. The results indicate that the surface roughness of the oxide scale increases as the final cooling (coiling) temperature increases, and the flow rate of …