Social and Behavioral Sciences Commons^™

Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Reactive power has become a vital resource in modern electricity networks due to increased penetration of distributed generation. This paper examines the extended reactive power capability of DFIGs to improve network stability and capability to manage network voltage profile during transient faults and dynamic operating conditions. A coordinated reactive power controller is designed by considering the reactive power capabilities of the rotor-side converter (RSC) and the grid-side converter (GSC) of the DFIG in order to maximise the reactive power support from DFIGs. The study has illustrated that, a significant reactive power contribution can be obtained from partially loaded DFIG wind …

Shear Lag And Eccentricity Effects Of Bolted Connections In Cold-Formed Steel Sections, Lip H. Teh, Veysel Yazici

Faculty of Engineering and Information Sciences - Papers: Part A

This paper examines the "three factors" approach previously presented by the senior author for determining the net section efficiency of a bolted cold-formed steel open profile. One objective is to ascertain that the net section efficiency is governed by three factors: the in-plane shear lag associated with stress concentration around a bolt hole that is also present in a flat sheet, the out-of-plane shear lag that is also present in a bi-symmetric I-section bolted at the flanges only, and the bending moment arising from the connection eccentricity with respect to the neutral axis. This paper presents the test results of …

Sample Design Using Imperfect Design Data, Robert Graham Clark

Faculty of Engineering and Information Sciences - Papers: Part A

A well-designed sampling plan can greatly enhance the information that can be produced from a survey. Once a broad sample design is identified, specific design parameters such as sample sizes and selection probabilities need to be chosen. This is typically achieved using an optimal sample design, which minimizes the variance of a key statistic or statistics, expressed as a function of design parameters and population characteristics, subject to a cost constraint. In practice, only imprecise estimates of population characteristics are available, but the effects of this variability are usually ignored. A general approach to sample allocation allowing for imprecise design …

Resonance Forever In A Rotational System: The Infinite Viv Lock-In Regime For Pivoted Cylinders, Brad Stappenbelt, Andrew Dennis Johnstone

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was …

An Equivalence Theorem For Reduced Fell Bundle C*-Algebras, Aidan Sims, Dana P. Williams

Faculty of Engineering and Information Sciences - Papers: Part A

We show that if E is an equivalence of upper semicontinu- ous Fell bundles B and C over groupoids, then there is a linking bundle L(E ) over the linking groupoid L such that the full cross-sectional alge- bra of L(E ) contains those of B and C as complementary full corners, and likewise for reduced cross-sectional algebras. We show how our re- sults generalise to groupoid crossed-products the fact, proved by Quigg and Spielberg, that Raeburn's symmetric imprimitivity theorem passes through the quotient map to reduced crossed products.

Evaluations Of Heuristic Algorithms For Teamwork-Enhanced Task Allocation In Mobile Cloud-Based Learning, Geng Sun, Jun Shen, Junzhou Luo, Jianming Yong

Faculty of Engineering and Information Sciences - Papers: Part A

Enhancing teamwork performance is a significant issue in mobile cloud-based learning. We introduce a service oriented system, Teamwork as a Service (TaaS), to realize a new approach for enhancing teamwork performance in the mobile cloud environment. To coordinate most learners' talents and give them more motivation, an appropriate task allocation is necessary. Utilizing the Kolb's learning style (KLS) to refine learner's capabilities, and combining their preferences and tasks' difficulties, we formally describe this problem as a constraint optimization model. Two heuristic algorithms, namely genetic algorithm (GA) and simulated annealing (SA), are employed to tackle the teamwork-enhanced task allocation, and their …

Measurement Of Multi-Slice Computed Tomography Dose Profile With The Dose Magnifying Glass And The Moskin Radiation Dosimeter, C P. L Lian, J H. D Wong, A Young, D Cutajar, M Petasecca, M L. F Lerch, Anatoly B. Rosenfeld

Faculty of Engineering and Information Sciences - Papers: Part A

This study describes the application of two in-house developed dosimeters, the Dose Magnifying Glass (DMG) and the MOSkin dosimeter at the Centre for Medical Radiation Physics, University of Wollongong, Australia, for the measurement of CT dose profiles for a clinical diagnostic 16-slice MSCT scanner. Two scanner modes were used; axial mode and helical mode, and the effect of varying beam collimation and pitch was studied. With an increase in beam collimation in axial mode and an increase of CT pitch in helical mode, cumulative point dose at scanner isocentre decreased while FWHM increased. There was generally good agreement to within …

Pricing Parisian And Parasian Options Analytically, Song-Ping Zhu, Wen-Ting Chen

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, two analytic solutions for the valuation of European-style Parisian and Par. asian options under the Black-Scholes framework are, respectively, presented. A key feature of our solution procedure is the reduction of a three-dimensional problem to a two-dimensional problem through a coordinate transform designed to combine the two time derivatives into one. Compared with some previous analytical solutions, which still require a numerical inversion of Laplace transform, our solutions, written in terms of double integral for the case of Parisian options but multiple integrals for the case of Par. asian options, are both of explicit form; numerical evaluation …

Collaborative Blind Source Separation Using Location Informed Spatial Microphones, Xiguang Zheng, Christian Ritz, Jiangtao Xi

Faculty of Engineering and Information Sciences - Papers: Part A

This letter presents a new Collaborative Blind Source Separation (CBSS) technique that uses a pair of location informed coincident microphone arrays to jointly separate simultaneous speech sources based on time-frequency source localization estimates from each microphone recording. While existing BSS approaches are based on localization estimates of sparse time-frequency components, the proposed approach can also recover non-sparse (overlapping) time-frequency components. The proposed method has been evaluated using up to three simultaneous speech sources under both anechoic and reverberant conditions. Results from objective and subjective measures of the perceptual quality of the separated speech show that the proposed approach significantly outperforms …

Fabrication And Characterisation Of Patterned Magnetorheological Elastomers, Weihua Li, Xianzhou Zhang, Tongfei Tian, Weijia Wen

Faculty of Engineering and Information Sciences - Papers: Part A

Magnetorheological elastomers (MREs) are composites that highly elastic polymer matrices are filled with magnetic particles. These materials exhibit unique characteristics that their modului can be controlled by an external magnetic field. This paper presents analysis, fabrication and characterization of novel patterned MREs. By taking into account the local magnetic field in MREs and particles' interaction magnetic energy, the magnetic field-dependent mechanical properties of MREs with lattice and BCC structures were theoretically analyzed and numerically simulated. Soft magnetic particles were assembled in polydimethylsioxane matrix to fabricate new MREs with uniformly lattice and BCC structures, which were observed by microscope. The field-dependent …

Displacement Profile Estimation Using Low Cost Inertial Motion Sensors With Applications To Sporting And Rehabilitation Exercises, James Coyte, David A. Stirling, Montserrat Ros, Haiping Du, Andrew Gray

Faculty of Engineering and Information Sciences - Papers: Part A

This paper investigates two methods of displacement estimation using sampled acceleration and orientation data from a 6 degrees of freedom (DOF) Inertial Measurement Unit (IMU), with the application to sporting training and rehabilitation. Currently, the use of low cost IMUs for this particular application is very impractical due to the accumulation of errors from various sources. Previous studies and projects that have applied IMUs to similar applications have used a lower number of DOF, or have used higher accuracy navigational grade IMUs. Solutions to the acceleration noise accumulation and gyroscope angle error problem are proposed in this paper. A zero …

A Novel Cost Effective Method For Vehicle Tire-Road Friction Coefficient Estimation, Boyuan Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

The tire-road friction coefficient is critical to vehicle longitudinal, lateral and roll dynamics and control because tire is the only contact part between the vehicle body and the road. However, direct measurement of tire-road friction coefficient is impossible in practice. This paper presents a novel cost effective method for vehicle tire-road friction coefficient estimation. This method only needs the measurements of the wheel angular velocity, the traction/brake torque and the longitudinal acceleration, which are all available from the commonly installed sensors in ordinary passenger vehicles, and can be used to estimate the individual tire-road friction coefficient. There are three steps …

Involvement Of Consumers In Health Technology Assessment Activities By Inahta Agencies, David Hailey, Sophie Werko, Rugayah Bakri, Alun Cameron, Britta Gohlen, Susan Myles, Jasmine Pwu, Jomkwan Yothasamut

Faculty of Engineering and Information Sciences - Papers: Part A

Objectives: To obtain further information from members of the International Network of Agencies for Health Technology Assessment (INAHTA) on the involvement of consumers in their programs. Methods: A questionnaire for a survey was developed and sent to member agencies in November 2010. Survey responses were compared with those from an earlier survey conducted in 2005. Results: Of the thirty-three agencies that provided responses, 67 percent involve consumers in some aspects of their health technology assessment (HTA) programs, compared with 57 percent in 2005. As in the earlier survey, most agencies reporting involvement have contact with consumer or patient organizations and …

Fairness In Concurrent Signatures Revisited, Willy Susilo, Man Ho Au, Yang Wang, Duncan S. Wong

Faculty of Engineering and Information Sciences - Papers: Part A

Concurrent signature, introduced by Chen, Kudla and Paterson, is known to just fall short to solve the long standing fair exchange of signature problem without requiring any trusted third party (TTP). The price for not requiring any TTP is that the initial signer is always having some advantage over the matching signer in controlling whether the protocol completes or not, and hence, whether the two ambiguous signatures will bind concurrently to their true signers or not. In this paper, we examine the notion and classify the advantages of the initial signer into three levels, some of which but not all …

Comment On "Equilibrium Conformation Of Polymer Chains With Noncircular Cross Section", Alexander Gerhardt-Bourke, Ngamta Thamwattana

Faculty of Engineering and Information Sciences - Papers: Part A

In this Comment, we point out that the Euler-Lagrange equations, which are referred to as the general equilibrium equations by Zhao are incorrect along with the equations which are derived from them. The correct equations are provided in this Comment. We produce new numerical results with the use of the correct equations. © 2013 American Physical Society.

Occurrence Of Surface Defects On Strips During Hot Rolling Process By Fem, Hai-Liang Yu, Kiet Tieu, Cheng Lu, Guan-Yu Deng, Xiang-Hua Liu

Faculty of Engineering and Information Sciences - Papers: Part A

During a hot rolling process, surface defects on strips can severely affect the quality of the rolled product, particularly for two conditions: (1) there are initial defects on continuous casting slabs that propagate and/or are inherited from those on the surface of rolled steels from upstream rolling processes; and (2) there are no initial defects on continuous casting slabs, and they consequently appear on the surface of rolled steels due to improper rolling technologies. In this paper, the authors present a new 3D finite element model coupled with constrained node failure to understand better the initiation and growth of surface …

Effect Of First Network Topology On The Toughness Of Double Network Hydrogels, Hai Xin, Sureyya Saricilar, Hugh Ralph Brown, Philip G. Whitten, Geoffrey Maxwell Spinks

Faculty of Engineering and Information Sciences - Papers: Part A

The fracture toughness of a double network (DN) hydrogel is shown here to be directly proportional to the toughness of the first-formed network. A series of DN gels was prepared in which the cross-link density of the first (tighter) network was controlled by varying the monomer and cross-linker concentrations. The toughness, tensile strength and elastic modulus of the DN gels increased significantly with an increase in the cross-link density of the first network and with identically prepared second networks. Moreover, the toughness of the double network was found to be linearly related to the toughness of the first network with …

Experimental And Theoretical Cross Sections For Positron Collisions With 3-Hydroxy-Tetrahydrofuran, Luca Chiari, Prasanga Palihawadana, J R. Machacek, Casten Makochekanwa, Gustavo Garcia, Francisco Blanco, R P. Mceachran, M J. Brunger, Stephen J. Buckman, James P. Sullivan

Faculty of Engineering and Information Sciences - Papers: Part A

Cross section results from a joint experimental and theoretical investigation into positron scattering from 3-hydroxy-tetrahydrofuran (3H-THF) are presented. Total and positronium (Ps) formation cross sections have been measured from 1 to 190 eV using the positron beamline at the Australian National University, which has an energy resolution between 60 and 100 meV. The total cross section (TCS) and the elastic and total inelastic integral cross sections in the energy range between 1 and 1000 eV have been computed within the Independent Atom Model using the Screening Corrected Additivity Rule approach. In addition, we have calculated elastic differential cross sections at …

Relations Among Privacy Notions For Signcryption And Key Invisible "Sign-Then-Encrypt", Yang Wang, Mark Manulis, Man Ho Allen Au, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

Signcryption simultaneously offers authentication through unforgeability and confidentiality through indistinguishability against chosen ciphertext attacks by combining the functionality of digital signatures and public-key encryption into a single operation. Libert and Quisquater (PKC 2004) extended this set of basic requirements with the notions of ciphertext anonymity (or key privacy) and key invisibility to protect the identities of signcryption users and were able to prove that key invisibility implies ciphertext anonymity by imposing certain conditions on the underlying signcryption scheme.

This paper revisits the relationship amongst privacy notions for signcryption. We prove that key invisibility implies ciphertext anonymity without any additional restrictions. …

A Three-Phase Power Flow Approach For Integrated 3-Wire Mv And 4-Wire Multigrounded Lv Networks With Rooftop Solar Pv, Md J E Alam, K M. Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

With increasing level of rooftop solar photovoltaic (PV) penetration into low voltage (LV) distribution networks, analysis with realistic network models is necessary for adequate capturing of network behavior. Traditional three-phase 3-wire power flow approach lacks the capability of exact analysis of 4-wire multigrounded LV networks due to the approximation of merging the neutral wire admittance into the phase wire admittances. Such an approximation may not be desirable when neutral wire and grounding effects need to be assessed, especially in the presence of single-phase solar power injection that may cause a significant level of network unbalance. This paper proposes a three-phase …

Critical Current Density: Measurements Vs. Reality, Alexey V. Pan, Igor Golovchanskiy, Sergey Fedoseev

Faculty of Engineering and Information Sciences - Papers: Part A

Different experimental techniques are employed to evaluate the critical current density (Jc), namely transport current measurements and two different magnetisation measurements forming quasi-equilibrium and dynamic critical states. Our technique-dependent results for superconducting YBa 2Cu3O7 (YBCO) film and MgB2 bulk samples show an extremely high sensitivity of Jc and associated interpretations, such as irreversibility fields and Kramer plots, which lose meaning without a universal approach. We propose such approach for YBCO films based on their unique pinning features. This approach allows us to accurately recalculate the magnetic-field-dependent Jc obtained by any technique into the Jc behaviour, which would have been measured …

A Molecular Dynamics Simulation Of Fracture In Nanocrystalline Copper, Linqing Pei, Cheng Lu, Kiet Tieu, Hongtao Zhu, Xing Zhao, Kuiyu Cheng, Liang Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

A large-scale molecular dynamics simulation was used to investigate the propagation of cracks in three dimensional samples of nanocrystalline copper, with average grain sizes ranging from 5.34 to 14.8 nm and temperatures ranging from 1K to 500 K. It was shown that intragranular fracture can proceed inside the grain at low temperature, and plastic deformation around the tip of the crack is accommodated by dislocation nucleation/emission; indeed, both fully extended dislocation and deformation twinning were visible around the tip of the crack during fracture. In addition, due to a higher concentration of stress in front of the crack at a …

Pseudo-Riemannian Spectral Triples And The Harmonic Oscillator, Koen Van Den Dungen, Mario Paschke, Adam C. Rennie

Faculty of Engineering and Information Sciences - Papers: Part A

We define pseudo-Riemannian spectral triples, an analytic context broad enough to encompass a spectral description of a wide class of pseudo-Riemannian manifolds, as well as their noncommutative generalisations. Our main theorem shows that to each pseudo-Riemannian spectral triple we can associate a genuine spectral triple, and so a K-homology class. With some additional assumptions we can then apply the local index theorem. We give a range of examples and some applications. The example of the harmonic oscillator in particular shows that our main theorem applies to much more than just classical pseudo-Riemannian manifolds. 2013 Elsevier B.V.

Teamwork As A Service: A Cloud-Based System For Enhancing Teamwork Performance In Mobile Learning, Geng Sun, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Although cloud computing helps learners to access online learning content through commonly used devices, it can be difficult to collaborate in the mobile environment. We develop a service-oriented system, ‘Teamwork as a Service’ (TaaS), to facilitate learners’ team learning activities. The five main services of TaaS facilitate a teamwork-enhanced learning flow associated with the theory of Kolb’s team learning experience, providing learners with an introduction, a ‘jigsaw classroom’, schedule planning, and mutual supervision during the whole process. Specifically, TaaS enables a rational grouping mechanism that allocates learners to their appropriate tasks in order to give their best performance. TaaS is …

Butyrate-Producing Clostridium Cluster Xiva Species Specifically Colonize Mucins In An In Vitro Gut Model, Pieter Van Den Abbeele, Clara Belzer, Margot Goossens, Michiel Kleerebezem, William M. De Vos, Olivier Thas, Rosemarie De Weirdt, Frederiek-Maarten Kerckhof, Tom Van De Wiele

Faculty of Engineering and Information Sciences - Papers: Part A

The human gut is colonized by a complex microbiota with multiple benefits. Although the surface-attached, mucosal microbiota has a unique composition and potential to influence human health, it remains difficult to study in vivo. Therefore, we performed an in-depth microbial characterization (human intestinal tract chip (HITChip)) of a recently developed dynamic in vitro gut model, which simulates both luminal and mucosal gut microbes (mucosal-simulator of human intestinal microbial ecosystem (M-SHIME)). Inter-individual differences among human subjects were confirmed and microbial patterns unique for each individual were preserved in vitro. Furthermore, in correspondence with in vivo studies, Bacteroidetes and Proteobacteria were enriched …

Facilitating Collaborative Learning In Taas: A Mobile Cloud System For Enhancing Teamwork Performance, Geng Sun, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Mobile cloud-based learning is a novel trend that brings many advantages to distributed learners to achieve collaborative learning, but it still lacks of mechanisms to enhance their teamwork performances. To make up that shortcoming, combining the features of cloud environment, we have identified a learning flow, a specification of workflow, based on Kolb team learning experience. This novel learning flow can be executed by our newly designed system, Teamwork as a Service (TaaS), in conjunction with cloud-hosting learning management systems, following which learners benefit from functions given by cloudbased services, separately for organizing cloud jigsaw classroom, planning and publishing tasks, …

A Biological Process Subject To Noncompetitive Substrate Inhibition In A Generalized Flow Reactor, M I. Nelson, T Nicholls, N Hamzah

Faculty of Engineering and Information Sciences - Papers: Part A

We analyse the steady-state operation of a continuous flow bioreactor in which the biochemical reaction is governed by noncompetitive substrate inhibition (Andrews kinetics). A generalized reactor model is used in which the well-stirred bioreactor and the idealized membrane bioreactor are special cases. As generic properties of systems subject to substrate inhibition have been obtained by other authors, we discuss reaction engineering features specific to Andrews kinetics.

Difference Between Far-Infrared Photoconductivity Spectroscopy And Absorption Spectroscopy: Theoretical Evidence Of The Electron Reservoir Mechanism, Tadashi Toyoda, Maho Fujita, Tomohisa Uchida, Nobuyoshi Hiraiwa, Taturo Fukuda, Hideki Koizumi, Chao Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

The intriguing difference between far-infrared photoconductivity spectroscopy and absorption spectroscopy in the measurement of the magnetoplasmon frequency in GaAs quantum wells reported by Holland et al. [Phys. Rev. Lett. 93, 186804 (2004)] remains unexplained to date. This Letter provides a consistent mechanism to solve this puzzle. The mechanism is based on the electron reservoir model for the integer quantum Hall effect in graphene [Phys. Lett. A 376, 616 (2012)]. We predict sharp kinks to appear in the magnetic induction dependence of the magnetoplasmon frequency at very low temperatures such as 14 mK in the same GaAs quantum well sample used …

Evidence-Free Policy: The Case Of The National Injury Insurance Scheme, Mark Harrison

Faculty of Engineering and Information Sciences - Papers: Part A

The Productivity Commission report 'Disability Care and Support' recommends tort liability be replaced by a compulsory, government-run, no-fault scheme. But theory and evidence indicate moving to a no-fault scheme will increase the accident rate. Even a move from non-risk-rated third-party insurance to non-risk-rated first-party insurance reduces incentives for care. A no-fault scheme is not superior to current policies; genuine reform will need to be informed by law and economics literature.

Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace

Faculty of Engineering and Information Sciences - Papers: Part A

Due to the current interest in organic printable electronics, Dip-Pen Nanolithography (DPN) is increasingly being explored as a method to pattern electroactive materials such as conducting polymers (CPs) on the micro- and nanoscale. In general, printing process depends strongly on the ink-substrate properties and fundamental forces required to drive and stabilize the ink transfer to the substrate. Controlling these parameters is especially difficult when operating under the nanometer confinements of the DPN probe. For the printing of CPs, one step towards addressing these challenges is rational ink design, as the use of existing commercial-based inks may not be suitable for …