Social and Behavioral Sciences Commons^™

Energy-Loss Rate Of A Fast Particle In Two-Dimensional Semiconductors With Rashba Spin-Orbit Coupling, Wei Feng, Asya Tawfiq, J.C Cao, Chao Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

The energy-loss rate (ELR) of a charged particle in a two-dimensional semiconductor with Rashba spin-orbit coupling is studied. Our model takes into account of the temperature and density dependence of the electronic properties of the Rashba system. The energy and temperature dependence of the ELR are presented. It is found that a finite Rashba spin-orbit coupling offers a mechanism of tuning the mean scattering time in narrow-gap semiconductors. With a change of Rashba parameter of around 3 times, the mean scattering time can change by one to two orders of magnitude. © 2013 American Institute of Physics.

Government Rail Asset Sales, And Return To The Public Sector, In New Zealand And Tasmania, Philip G. Laird

Faculty of Engineering and Information Sciences - Papers: Part A

The paper outlines the sale, with a track lease, in 1993 of the state owned New Zealand Railways Corporation to a consortium, TranzRail Holdings formed by the United States and New Zealand interests. It also notes increases in productivity and traffic levels to 1999 with subsequent problems leading to the New Zealand Government agreeing in 2003 to repurchase and rehabilitate the track. The paper then outlines transfer of effective ownership of the trains and related services in 2003 to an Australian company, and in 2008 back to the New Zealand Government at appreciable net cost.After a brief outline of railways …

Semi-Finite Noncommutative Geometry And Some Applications, Alan L. Carey, Adam C. Rennie, John Phillips

Faculty of Engineering and Information Sciences - Papers: Part A

These notes are a summary of talks given in Shonan, Japan in February 2008 with modifications from a later series of talks at the Hausdorff Institute for Mathematics in Bonn in July 2008 and at the Erwin Schr¨odinger Institute in October 2008. The intention is to give a short discussion of recent results in noncommutative geometry (NCG) where one extends the usual point of view of [22] by replacing the bounded operators B(H) on a Hilbert space H by certain sub-algebras; namely semi-finite von Neumann algebras. These are weakly closed subalgebras of the bounded operators on a Hilbert space that …

The Local Index Formula In Noncommutative Geometry Revisited, Alan L. Carey, John Phillips, Adam C. Rennie, Fyodor A. Sukochev

Faculty of Engineering and Information Sciences - Papers: Part A

In this review we discuss the local index formula in noncommutative geomety from the viewpoint of two new proofs are partly inspired by the approach of Higson especially that in but they differ in several fundamental aspedcts, in particular they apply to semifinite spectral triples for a *s-subalgebra A of a general semifinite von Neumann algebra. Our proofs are novel even in the setting of the original theorem and reduce the hypotheses of the theorem to those necessary for its statement.

These proofs rely on the introduction of a function valued cocycle which is 'almost' a (b, B)-cocycle in the …

Influence Of External Optical Feedback On The Alpha Factor Of Semiconductor Lasers, Yanguang Yu, Jiangtao Xi

Faculty of Engineering and Information Sciences - Papers: Part A

This Letter presents the results revealing the influence of external optical feedback (EOF) on the alpha factor, or the linewidth enhancement factor, of semiconductor lasers operating on single mode. First, a method is proposed for the measurement of the alpha over a wide range of optical feedback level, which provides an effective way for investigating the dependence of the alpha on laser operating conditions. Second, experimental investigation based on the proposed method is performed on a GaAlAs laser diode with a multiquantum well structure. It is discovered that the alpha value remains approximately constant with increasing injection current, but has …

Impact Of Patient Rotational Errors On Target And Critical Structure Dose In Imrt: A 3d Simulation Study, S Arumugam, A Xing, P Vial, A Scotti, R Stirton, G Goozee, Lois Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30 to +30 was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to …

Approximation Algorithm For Data Broadcasting In Duty Cycled Multi-Hop Wireless Networks, Dianbo Zhao, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

Broadcast is a fundamental operation in wireless networks. To this end, many past studies have studied the NP-hard, broadcast problem for always-on multi-hop networks. However, in wireless sensor networks, nodes are powered by batteries, meaning, they have finite energy. Consequently, nodes are required to have a low duty cycle, whereby they switch between active and sleep state periodically. This means that a transmission from a node may not reach all of its neighbors simultaneously. Consequently, any developed broadcast protocols must consider collisions and the wake-up times of neighboring nodes. Henceforth, this paper studies the minimum latency broadcast scheduling problem in …

Distribution Of Reynolds Shear Stress In Steady And Unsteady Flows, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar

Faculty of Engineering and Information Sciences - Papers: Part A

This study investigates the Reynolds shear stress distribution in steady and unsteady non-uniform flows. Specifically, it deals with how to express the deviation of this turbulence characteristic from that of uniform flow line; it is found that flow acceleration can well represent the deviation of Reynolds shear stress from its standard linear distribution. By connecting the flow acceleration with Reynolds shear stress, the study demonstrates empirically that the linear distrubiton of Reynolds shear stress can be observed when the flow acceleration is zero; the concave distribution of Reynolds shear stress can be observed when the flow acceleration is negative or …

Total Electron-Scattering Cross Sections From Pyrimidine As Measured Using A Magnetically Confined Experimental System, Martina C. Fuss, Ana G. Sanz, Francisco Blanco, Juan Carlos Oller, Paulo Limao-Vieira, Michael J. Brunger, Gustavo Garcia

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, an apparatus for measuring electron-scattering cross sections while applying a strong axial magnetic field is described. The first original experiment performed with this setup is the measurement of the total cross sections for pyrimidine (1,3-diazine), which are presented for the incident electron energy range of 8-500 eV. Generally good agreement with earlier theoretical predictions is found after accounting for the angular acceptance (angular resolution for forward scattering) of the apparatus.

Identity-Based Multisignature With Message Recovery, Kefeng Wang, Yi Mu, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

We present a new notion of short identity-based multisignature scheme with message recovery. We propose a concrete identity-based multisignature with message recovery scheme based on bilinear pairing in which multiple signers can generate a constant size multisignature on same message regardless of the number of signers. There is no requirement to transmit the original message to the verifier, since the original message can be recovered from the multisignature. Therefore, this scheme minimizes the total length of the original message and the appended multisignature. The proposed scheme is proven to be existentially unforgeable against adaptively chosen message attacks in the random …

A Unique Sandwich-Structured C/Ge/Graphene Nanocomposite As An Anode Material For High Power Lithium Ion Batteries, Dan Li, Kuok H. Seng, Dongqi Shi, Zhixin Chen, Hua-Kun Liu, Zaiping Guo

Faculty of Engineering and Information Sciences - Papers: Part A

A unique sandwich-structured C/Ge/graphene composite with germanium nanoparticles trapped between graphene sheets is prepared by a microwave-assisted solvothermal reaction followed by carbon coating and thermal reduction. The graphene sheets are found to be effective in hindering the growth and aggregation of GeO2 nanoparticles. More importantly, the graphene sheets, coupled with the carbon coating, can buffer the volume changes of germanium in electrochemical lithium reactions. The unique sandwich structure features a highly conductive network of carbon, which can improve both the conductivity and the structural stability of the electrode material, and exemplifies a promising strategy for the development of new high …

Rectifying Differences In Transport, Dynamic, And Quasi-Equilibrium Measurements Of Critical Current Density, I A. Golovchanskiy, A V. Pan, O V. Shcherbakova, S A. Fedoseev

Faculty of Engineering and Information Sciences - Papers: Part A

The dependence of the critical current density (J_c ) on electric field criteria (E _cr) is studied for high-quality YBCO (YBa₂Cu₃O₇) thin films over the entire applied magnetic field (B_a) range. The quantitative model describing the J_c(B_a) dependence is compared and explained for the critical current densities obtained by different measurement techniques. Transport current and quasi-equilibrium magnetization measurement data can successfully be fitted by the model with appropriate electric field criteria. The dependence of the irreversibility field on the E _cr criterion can be obtained within …

Enhancing Impact Fracture Toughness And Tensile Properties Of A Microalloyed Cast Steel By Hot Forging And Post-Forging Heat Treatment Processes, Jingwei Zhao, Zhengyi Jiang, Chong Soo Lee

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, the effects of hot forging and post-forging heat treatment on the impact fracture toughness and tensile properties of a microalloyed cast steel were investigated. Mechanical tests were used to evaluate the room temperature impact fracture toughness and tensile properties of the steel. The resulting microstructures were analysed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The extraction replica technology was used to investigate the characterisation of complex precipitates formed during heat treatment. The obtained results showed that the coarse-grained microstructure of the forged specimen was significantly refined after post-forging heat treatment. …

Enhancing Mechanical Properties Of A Low-Carbon Microalloyed Cast Steel By Controlled Heat Treatment, Jingwei Zhao, Jeong Hun Lee, Yong Woo Kim, Zhengyi Jiang, Chong Soo Lee

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, detailed studies were made on the optimization of microstructure and mechanical properties of a low-carbon microalloyed cast steel through control of heat treatment conditions. Specimens were austenitized at temperatures ranging from 950 to 1200 °C for 2 h followed by different cooling methods (furnace, air and water). For analyzing the effect of holding time on mechanical properties, some cast specimens were austenitized at 1100 °C for different times followed by furnace cooling. After heat treatment, mechanical tests were employed to evaluate the room temperature Charpy impact and tensile properties. The characterization of complex precipitates formed during …

Predicting Additive And Non-Additive Genetic Effects From Trials Where Traits Are Affected By Interplot Competition, Colleen H. Hunt, Alison B. Smith, David R. Jordan, Brian R. Cullis

Faculty of Engineering and Information Sciences - Papers: Part A

There are two key types of selection in a plant breeding program, namely selection of hybrids for potential commercial use and the selection of parents for use in future breeding. Oakey et al. (in Theoretical and Applied Genetics 113, 809-819, 2006) showed how both of these aims could be achieved using pedigree information in a mixed model analysis in order to partition genetic effects into additive and non-additive effects. Their approach was developed for field trial data subject to spatial variation. In this paper we extend the approach for data from trials subject to interplot competition. We show how the …

Utilising Confinement Reinforcement For Shear Resistance In Reinforced Concrete Structures, Kamal Jaafar

Faculty of Engineering and Information Sciences - Papers: Part A

Common transverse reinforcement of reinforced concrete members with circular cross-section consists of round ties or spirals. Its purpose in members that are not subjected to significant shear loading is to provide proper confinement for concrete, and eliminate buckling of the longitudinal reinforcement bars. If spirals are to be used as both shear enabler and confiner for reinforced concrete beams then, under combined action of moment and shear, spirals will be required to provide or contribute to proper shear resistance. Hence, a proper assessment for spiral shear contribution is required. The validity of concepts which underline current methods for shear design …

Modeling Dense-Phase Pneumatic Conveying Of Powders Using Suspension Density, S S. Mallick, P W. Wypych, R Pan

Faculty of Engineering and Information Sciences - Papers: Part A

This article presents results of an investigation into the modeling of pressure drop in horizontal straight pipe section for fluidized dense-phase pneumatic conveying of powders. Suspension density and superficial air velocity have been used to model pressure drop for two-phase solids-gas flow. Two applicable models formats (developed by other researchers using two different definitions of suspension density) were used to represent the pressure drop due to solids-gas flow through straight pipe sections. Models were generated based on the test data of conveying power-station fly ash and electrostatic precipitator (ESP) dust (median particle diameter: 30 and 7 µm; particle density: 2300 …

Transmit Antenna Subset Selection With Power Balancing For High Data Rate Mimo-Ofdm Uwb Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes per-subcarrier transmit antenna subset selection with power balancing for MIMO-OFDM UWB systems to simultaneously improve the system error performance and increase data rates. The deployment of the per-subcarrier antenna subset selection may result in a power unbalance across antennas, which could cause power amplifiers (PAs) to operate in their non-linear regions. To overcome this disadvantage, we formulate a linear optimization problem for the optimal allocation of data subcarriers under a constraint that all antennas have the same number of assigned data symbols. This optimization problem could be applied to systems with an arbitrary number of multiplexed data …

The Role Of Public Procurement In Improving Accessibility To Ict, Gunela Astbrink, William Tibben

Faculty of Engineering and Information Sciences - Papers: Part A

Government bodies use public procurement policies and mechanisms to purchase ICT products and services. Some governments in OECD countries apply accessibility criteria when procuring ICT to improve access to their services and employment opportunities for people with disabilities. This may have a flow-on effect of greater availability of affordable and accessible ICT thus improving digital inclusion. This paper outlines research on comparative analysis of the situation in Australia with current policy in OECD countries. The research resulted in recommendations for a consumer-oriented plan to work with Australian governments on the introduction of accessibility criteria in ICT public procurement.

Impact Of Humic Acid Fouling On Membrane Performance And Transport Of Pharmaceutically Active Compounds In Forward Osmosis, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech

Faculty of Engineering and Information Sciences - Papers: Part A

The impact of humic acid fouling on the membrane transport of two pharmaceutically active compounds (PhACs) - namely carbamazepine and sulfamethoxazole - in forward osmosis (FO) was investigated. Deposition of humic acid onto the membrane surface was promoted by the complexation with calcium ions in the feed solution and the increase in ionic strength at the membrane surface due to the reverse transport of NaCl draw solute. The increase in the humic acid deposition on the membrane surface led to a substantial decrease in the membrane salt (NaCl) permeability coefficient but did not result in a significant decrease in the …

Influence Of Fluoride And Chromium(Vi) Ions On Corrosion Mechanisms Of Pb-3wt%Sn-0.5wt%Ag Anode, Jianzhong Li, Xiuli Sun, Yanwen Tian, Yue Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

A mix solution of fluorine and chromium ions (Cr-F solution) for applications in chromium plating field has a characteristic of strong corrosion and oxidation, promoting lead alloys anode degraded rapidly. The present study explores the time dependence on corrosion mechanisms of lead alloys anode oxidised in Cr-F solution under conditions of high current density. Scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscopy (EDX) shows a double-layer oxide film is electrochemically developed on lead alloys anode after oxidation for above 0.5h. The outer layer is primarily PbO and PbO2, and the inner layer contains PbCrO4 and PbF2, followed by …

Integrating Iterative Crossover Capability In Orthogonal Neighborhoods For Scheduling Resource-Constrained Projects, Reza Zamani

Faculty of Engineering and Information Sciences - Papers: Part A

An effective hybrid evolutionary search method is presented which integrates a genetic algorithm with a local search. Whereas its genetic algorithm improves the solutions obtained by its local search, its local search component utilizes a synergy between two neighborhood schemes in diversifying the pool used by the genetic algorithm. Through the integration of these two searches, the crossover operators further enhance the solutions that are initially local optimal for both neighborhood schemes; and the employed local search provides fresh solutions for the pool whenever needed. The joint endeavor of its local search mechanism and its genetic algorithm component has made …

Microtexture Based Analysis Of Surface Asperity Flattening Behavior Of Annealed Aluminum Alloy In Uniaxial Planar Compression, Hejie Li, Zhengyi Jiang, Dongbin Wei, Xiaoming Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

During the uniaxial planar compression of annealed aluminum alloy, a novel approach to determine surface asperity flattening (roughness Ra) is employed by analyzing the evolution of surface microtexture. With an increase in gauged reduction, surface asperity tends to be flattened, and strain hardening increases. Lubrication can constrain the surface asperity flattening process. Development of surface asperity features shows the obvious dependency on [111] orientation. In-grain slips contribute significantly to the evolution of surface microtexture. Influence of deformation twins (brass orientation) on the evolution of microtexture is not obvious under our current experimental conditions.

Remarks On Some Fundamental Results About Higher-Rank Graphs And Their C*-Algebras, Robert Hazlewood, Iain Raeburn, Aidan Sims, Samuel B. G Webster

Faculty of Engineering and Information Sciences - Papers: Part A

Results of Fowler and Sims show that every k-graph is completely determined by its k-coloured skeleton and collection of commuting squares. Here we give an explicit description of the k-graph associated with a given skeleton and collection of squares and show that two k-graphs are isomorphic if and only if there is an isomorphism of their skeletons which preserves commuting squares. We use this to prove directly that each k-graph. is isomorphic to the quotient of the path category of its skeleton by the equivalence relation determined by the commuting squares, and show that this extends to a homeomorphism of …

Tribological Properties Of Magnetite Precipitate From Oxide Scale In Hot-Rolled Microalloyed Steel, Xianglong Yu, Zhengyi Jiang, Dongbin Wei, Cunlong Zhou, Qingxue Huang, Daijun Yang

Faculty of Engineering and Information Sciences - Papers: Part A

Nano-magnetite (Fe3O4) particles have a potential to lead to the formation of lubrication tribofilm that reduces the friction and wear in hot steel strip rolling. In this paper, an attempt to fabricate the oxide film with magnetite precipitates from thermally-grown wustite (Fe1-xO) layer during isothermal cooling of low carbon microallyed steel, was obtained. The precipitation behaviors were investgated on Gleeble 3500 thermo-mechanical simulator under the humid air with water vaour content of 19.5 per vol percent. Several types of magnetite precipitates were examined using scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. The tribological …

Enhanced Through-The-Wall Radar Imaging Using Bayesian Compressive Sensing, V H. Tang, A Bouzerdoum, S L. Phung, F H. C Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a distributed compressive sensing (CS) model is proposed to recover missing data samples along the temporal frequency domain for through-the-wall radar imaging (TWRI). Existing CS-based approaches recover the signal from each antenna independently, without considering the correlations among measurements. The proposed approach, on the other hand, exploits the structure or correlation in the signals received across the array aperture by using a hierarchical Bayesian model to learn a shared prior for the joint reconstruction of the high-resolution radar profiles. A backprojection method is then applied to form the radar image. Experimental results on real TWRI data show …

Modeling And Experimental Investigation Of Rotational Resistance Of A Spiral-Type Robotic Capsule Inside A Real Intestine, Hao Zhou, Gursel Alici, Trung Duc Than, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

In this study, the rotational resistance of a spiral-type capsule rotating inside a small intestine is investigated by in vitro experiments and analytical modeling, on which a limited literature is available. The results presented exhibit viscoelastic nature of the intestinal tissue. The significance of various spiral structures and rotating speeds is quantitatively evaluated from the propulsion point of view. Also, an analytical torque model is proposed and subsequently validated. The close match between the experimental results and numerical results from the model shows that the model is reasonably accurate to estimate the rotational resistance torque of the small intestine. Both …

Sizing Optimization Of Trapezoidal Corrugated Roof Sheeting, Supporting Solar Panels, Under Wind Loading, P Sharafi, Lip H. Teh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

The dimensions of trapezoidal roof sheeting supporting solar panels are optimized so that a minimum amount of steel is required for a specific range of wind loads. Sheets of different grades and different thicknesses along with different ranges of wind speeds are considered. In order to simulate the behavior of the corrugated sheets analysis is carried out for two limit states: strength and serviceability. For both limit states, the objective is to minimize the weight per unit area of the panels. First, optimum cross-section is obtained to meet the strength conditions. Then the deflection is controlled for serviceability. The optimum …

Towards Improved Steel Alloy Designs For Control Of Weld Heat Affected Zone Properties, F J. Barbaro, Z Zhu, L Kuzmikova, H Li, J M. Gray

Faculty of Engineering and Information Sciences - Papers: Part A

This paper reviews the current technology related to control of weld HAZ properties in high strength steels. The debate related to appropriate balance of Ti and N is addressed and it appears that a stoichiometric ratio provides optimum fracture toughness. The results are significant because despite the well established difficulties in controlling Ti/N ratio, this data now provides guidance in terms of alloy design to achieve optimum fracture toughness in the HAZ of welds. The enhanced resistance to grain coarsening behaviour of high Nb steels has now provided another incremental improvement in the weldability of steels for critical applications such …

Security Analysis Of A Distributed Reprogramming Protocol For Wireless Sensor Networks, Yong Yu, Jianbing Ni, Ying Sun

Faculty of Engineering and Information Sciences - Papers: Part A

Reprogramming for wireless sensor networks is essential to upload new code or to alter the functionality of existing code. To overcome the weakness of the centralized approach of the traditional solutions, He et al. proposed the notion of distributed reprogramming where multiple authorized network users are able to reprogram sensor nodes without involving the base station. They also gave a novel distributed reprogramming protocol called SDRP by using identity-based signature, and provided a comprehensive security analysis for their protocol. In this letter, unfortunately, we demonstrate that SDRP is insecure as the protocol fails to satisfy the property of authenticity and …