Social and Behavioral Sciences Commons^™

Comparison Of Methodologies For Assessment Of Harmonic Current Emission Limits For Large Installations Connected To Lv Networks, Biyanvilage Perera, Sarath Perera, Philip Ciufo, Victor J. Gosbell

Faculty of Engineering and Information Sciences - Papers: Part A

With the proliferation of large, disturbing installations (loads and distribution generators) connected to public low voltage networks, managing the harmonic voltage levels in the network has become a key concern to distribution network service providers (DNSPs). Therefore, it is important that DNSPs limit the harmonic current emission by individual installations. This paper reviews a number of methodologies that exist in the current technical literature in relation to the assessment of harmonic current emission limits for disturbing installations connected to the public LV network. Application of these methodologies is demonstrated through a case study on a test network. The study shows …

Round-Optimal Id-Based Blind Signature Schemes Without Ros Assumption, Wei Gao, Guilin Wang, Xueli Wang, Fei Li

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents two Identity-Based Blind Signature (IBBS) schemes based on bilinear pairings. Both of them enjoy the following features. First, they achieve the optimal bound of round complexity for blind signatures, i.e., each signature can be blindly generated with one round (or two moves) of message exchanges between the signature requesting user and signer. Second, their security is proved without the ROS assumption, which assumes that it is infeasible to find an overdetermined, solvable system of linear equations modulo q with random inhomogenities. Due to this reason, the order of underlying group does not need to be very large …

Impact Of Mains Connected Three-Phase Induction Motor Loading Levels On Network Voltage Unbalance Attenuation, Upuli Jayatunga, Sarath Perera, Philip Ciufo

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage unbalance (VU) in power systems should be managed in a systematic manner in order to minimise its adverse effects on both customer equipment and supply utilities. It is a well known fact that three-phase induction motor performance can be significantly affected in the presence of supply voltage unbalance. It is also known that three-phase induction motors can help to reduce pre-existing network voltage unbalance levels. Recently undertaken research aligned with IEC/TR 61000-3-13:2008 Technical Report on voltage unbalance management (emission allocation and emission assessment) have quantified the contribution made by induction motors to the net voltage unbalance at a point …

Investigation On Welding Arc Interruptions In The Presence Of Magnetic Fields: Arc Length, Torch Angle And Current Pulsing Frequency Influence, Ruham Pablo Reis, Americo Scotti, John Norrish, Dominic Cuiuri

Faculty of Engineering and Information Sciences - Papers: Part A

Arc interruptions have been observed in tandem pulsed gas metal arc welding (GMAW). This fact, which is likely related to magnetic interaction between the arcs, motivated previous study concerning the influence of the welding current on this phenomenon. In order to promote further understanding, this paper investigates the effects of arc length, torch angle, and high-frequency current pulsing on the arc resistance to extinction. To mimic the situation found in tandem GMAW (magnetic field induced by one arc acting on the other arc), external magnetic fields were applied to gas tungsten arc welding arcs. It was verified that short arc …

Inclusion Of Mobile Phone Numbers Into An Ongoing Population Health Survey In New South Wales, Australia: Design, Methods, Call Outcomes, Costs And Sample Representativeness, Margo Barr, Jason J. Van Ritten, David G. Steel, Sarah V. Thackway

Faculty of Engineering and Information Sciences - Papers: Part A

Background: In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant …

Data Driven Encoding Of Structures And Link Predictions In Large Xml Document Collections, M Hagenbuchner, A C. Tsoi, M Kc, Shujia Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

In recent years there have been some significant research towards the ability of processing related data, particularly the relatedness among atomic elements in a structure with those in another structure. A number of approaches have been developed with various degrees of success. This chapter provides an overview of machine learning approaches for the encoding of related atomic elements in one structure with those in other structures. The chapter briefly reviews a number of unsupervised approaches for such data structures which can be used for solving generic classification, regression, and clustering problems. We will apply this approach to a particularly interesting …

Analysis Of Voltage Quality Data From Smart Meters, P K. C Wong, R A. Barr, A Kalam

Faculty of Engineering and Information Sciences - Papers: Part A

Initial analysis of voltage quality information collected from smart meters at premise level is presented. The information reveals instances of over and under voltage at some consumer premises. This revelation means supply authorities now have an obligation to rectify their supply voltages in accordance with codes and regulations. The analysis provides the foundation for future research work to identify effective solutions to the observed over and under voltage problems in the supply network. © 2012 Institut Teknologi Sepulul.

Predication Of The Behaviour Of Bulk Materials In The Design And Operation Of Bulk Handling And Processing Plants, David Hastie, Peter Wypych, Andrew Grima, Richard La Roche, David Curry

Faculty of Engineering and Information Sciences - Papers: Part A

It is very dangerous to assume or extrapolate anything when it comes to bulk material properties and behaviour. Traditional methods for flow prediction, such as hand calculation or even just relying on past experience, require assumptions to be made about the bulk material properties and flow. Although these materials may have generic names and possess similar properties (e.g. coal, iron ore), they can all behave quite differently under dynamic conditions. What we end up designing for one part of the plant may be quite different to what is needed in another part of the plant, which may be handling or …

Robust Yaw Moment Control For Vehicle Handling And Stability, Haiping Du, Nong Zhang, Wade Smith

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a robust yaw moment controller design approach for improving vehicle handling and stability. With considering the parameter-varying property of tyre cornering stiffness in extreme handling situations, a linear parameter-varying (LPV) model in polytopic form is constructed to represent the nonlinear characteristics of tyres. A yaw moment controller is then designed for the LPV model which aims at optimising the tracking performance on both yaw rate and sideslip angle with respect to their targets. The conditions for designing such a controller are derived in terms of linear matrix inequalities (LMIs). Numerical simulations on a nonlinear vehicle model are …

Exploring Technological-Organizational And Environmental Characteristics Related To Rfid Adoption Intention In The Saudi Arabia's Retail Industry, Salem Alqahtani, Samuel Fosso Wamba

Faculty of Engineering and Information Sciences - Papers: Part A

Drawing on the diffusion of innovation (DOI) theory as well as on the emerging literature on RFID technology, this study explores a set of technological, organizational and environmental characteristics that will play an important role in the RFID adoption decision process within the Saudi retail industry. Results of data collected among seven (7) Saudi large-scale retailers are presented and discussed, together with the implications for research and practice.

Realising The C*-Algebra Of A Higher-Rank Graph As An Exel's Crossed Product, Nathan Brownlowe

Faculty of Engineering and Information Sciences - Papers: Part A

We use the boundary-path space of a finitely-aligned k-graph Lambda to construct a compactly-aligned product system X, and we show that the graph algebra C*(Lambda) is isomorphic to the Cuntz-Nica-Pimsner algebra NO(X). In this setting, we introduce the notion of a crossed product by a semigroup of partial endomorphisms and partially-defined transfer operators by defining it to be NO(X). We then compare this crossed product with other definitions in the literature.

Distributed Energy Storage For Mitigation Of Voltage-Rise Impact Caused By Rooftop Solar Pv, M J. E Alam, K M. Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

A high penetration of solar photovoltaic (PV) resources into distribution networks may create voltage rise problem when the generation from PV resources substantially exceeds the load demand. To reduce the voltage rise, the excess amount of power from the solar PV units needs to be reduced. In this paper, distributed storage systems are proposed for the mitigation of voltage rise problem. The surplus energy from the solar PV is used to charge the distributed storage units during midday, when the power from the solar PV would be typically higher than the load level. This stored energy is then used to …

Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson

Faculty of Engineering and Information Sciences - Papers: Part A

Microgrids are becoming important constituents of electric power distribution networks. Microgrids are typically comprised of both inverter interfaced (e.g. double-fed induction generator (DFIG), solar-photovoltaic (PV) system) and non-inverter interfaced (e.g. synchronous generator) renewable energy generators (REGs), hence their dynamic characteristics are significantly different from the conventional grids comprised of centralised synchronous generators. Different inherent characteristics of REGs, power dispatch levels, relative REG capacities, and external grid characteristics are some of the important features of significant interest in relation to microgrid dynamic behaviour. For this study a microgrid model was developed in DIgSILENT Power Factory based on the IEEE-13 bus system …

Impact Of Wind Generator Control Strategies On Flicker Emission In Distribution Networks, Lasantha Meegahapola, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Renewable power generators are increasingly being integrated to electricity networks to achieve future renewable energy targets in power generation. In particular, wind power generation has already reported substantial penetration levels in electricity networks. Traditionally, flicker phenomenon is considered to be one of the power quality issues in power distribution networks due to fluctuating consumer loads connected to the network. Large-scale integration of wind power generators may create significant voltage fluctuations in distribution feeders due to stochastic and intermittent nature of the wind resources. This study aims to investigate and characterize the flicker emission under different control strategies for DFIG based …

Evaluating Disaster Management Knowledge Model By Using A Frequency-Based Selection Technique, Siti Hajar Othman, Ghassan Beydoun

Faculty of Engineering and Information Sciences - Papers: Part A

Disaster Management (DM) is a multidisciplinary endeavour and a very difficult knowledge domain to model. It is a diffused area of knowledge that is continuously evolving and informally represented. Metamodel is the output artefact of metamodelling, a software engineering approach, which makes statements about what can be expressed in the valid models of the knowledge domain. It is an appropriate high level knowledge structure to facilitate it being communicated among DM stakeholders. A Disaster Management Metamodel (DMM) is developed. To satisfy the expressiveness and the correctness of a DMM, in this paper we present a metamodel evaluation technique by using …

Estimation Of Breeding Values For Mean And Dispersion, Their Variance And Correlation Using Double Hierarchical Generalized Linear Models, M Felleki, D Lee, Y Lee, A R. Gilmour, L Ronnegard

Faculty of Engineering and Information Sciences - Papers: Part A

The possibility of breeding for uniform individuals by selecting animals expressing a small response to environment has been studied extensively in animal breeding. Bayesian methods for fitting models with genetic components in the residual variance have been developed for this purpose, but have limitations due to the computational demands. We use the hierarchical (h)-likelihood from the theory of double hierarchical generalized linear models (DHGLM) to derive an estimation algorithm that is computationally feasible for large datasets. Random effects for both the mean and residual variance parts of the model are estimated together with their variance/covariance components. An important feature of …

Cognitive Processes In Object-Oriented Requirements Engineering Practice: Analogical Reasoning And Mental Modelling, Linda Dawson

Faculty of Engineering and Information Sciences - Papers: Part A

This chapter presents a background in cognitive processes such as problem-solving and analogical reasoning for considering modelling from an object-oriented perspective within the domain of requirements engineering. This chapter then describes a research project and the findings from a set of four cases which examine professional practice from perspective of cognitive modelling for object-oriented requirements engineering. In these studies, it was found that the analysts routinely built models in their minds and refined them before committing them to paper or communicating these models to others. The studies also showed that object-oriented analysts depend on analogical reasoning where they use past …

Very High Data Rate Mb-Ofdm Uwb Systems With Transmit Diversity Techniques, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, the application of space time block codes in a very high data rate multiband-OFDM ultra-wideband (VHDR MB-OFDM UWB) system, where the Modified Dual Carrier Modulation (MDCM) scheme and Low Density Parity Check codes are deployed, is investigated. First, we present a new table-based mapping approach and derive soft-demapping expressions for the MDCM scheme. We then propose a space-time-frequency coded VHDR MB-OFDM UWB system by incorporating space time block codes into the conventional VHDR MB-OFDM UWB system. Numerical simulations of the system supporting a data rate of 1Gbps over the IEEE 802.15.3a channel models are implemented. The simulation …

Reducing Unwarranted Variation In Healthcare Service Delivery Systems: Key Issues, Research Challenges And Potential Solutions, Nagesh Shukla, Senevi Kiridena, Nishikant Mishra

Faculty of Engineering and Information Sciences - Papers: Part A

There is a growing need worldwide to increase the quality and productivity of healthcare services delivery. To this end, analysing and reducing unwarranted variations in healthcare has attracted much attention in recent times. However, current modelling and simulation approaches to reduce unwarranted variations suffer from numerous limitations. Consequently, service improvement efforts have often failed to deliver expected results. This paper discusses the key issues associated with reducing unwarranted variations in hospital service delivery systems, and proposes a research framework that aims at overcoming these issues. In doing so, it highlights the need for: accurately and efficiently modelling complex service delivery …

Complementary Techniques For Probing Terahertz Magnetic Excitations In Cu3bi(Seo3)2o2cl, K H. Miller, E Constable, H Berger, D B. Tanner, J Horvat, R A. Lewis

Faculty of Engineering and Information Sciences - Papers: Part A

A low frequency magnetic excitation in Cu3Bi(SeO 3)2O2Cl has been studied through complementary spectroscopic techniques which utilised terahertz radiation from a synchrotron, a mercury arc lamp, and a two-colour photomixing system. The excitation has been studied at temperatures down to 5K and in magnetic fields up to 10T. © 2012 IEEE.

Nonlinear Optical Response Of Graphene Superlattice In Terahertz Frequency Regime, Yee Sin Ang, Chao Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

We investigate the nonlinear optical response of a Kronig-Penney type graphene superlattice in which the Fermi velocity of the massless Dirac quasiparticle anisotropically depends on the direction of propagation. Such velocity anisotropy results in enhanced nonlinear optical response in terahertz frequency regime.

Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood

Faculty of Engineering and Information Sciences - Papers: Part A

Acoustic emission (AE) monitoring has been used to detect split formation during room temperature low blow Charpy impact testing of high strength thick strip steels. The AE signal analysis identified separate signals originating from hammer impact, plastic deformation (verified using Charpy impact testing on mild steel with no splits) and split initiation/growth. The presence of splits was confirmed by sectioning and fractography, and the splits were brittle in nature. A possible correlation between the AE signal features and fracture mode is presented.

Methods For Usability Evaluations Of Mobile Devices, Fayez Alshehri, Mark Freeman

Faculty of Engineering and Information Sciences - Papers: Part A

The usability of applications designed and developed for mobile devices integral user experience, particularly for current touch-screen mobile devices. This conceptual paper provides a profile of the ways in which mobile device usability evaluation methods are being adapted to better reflect technological. With an increasing capacity for greater user interactivity through a range of tasks and in a variety of contexts, the importance and impact of mobile device context-of-use components is of particular interest to researchers. This requires a need for a shift in evaluation method paradigms with a particular focus on methods involving the user, as part of the …

Electron Emission From Amorphous Solid Water After Proton Impact: Benchmarking Ptra And Geant4 Track Structure Monte Carlo Simulations, M U. Bug, H Rabus, Anatoly B. Rosenfeld

Faculty of Engineering and Information Sciences - Papers: Part A

Track structure Monte Carlo simulations of ionising radiation in water are often used to estimate radiation damage to DNA. For this purpose, an accurate simulation of the transport of densely ionising low-energy secondary electrons is particularly important, but is impaired by a high uncertainty of the required physical interaction cross section data of liquid water.

A possible tool for the verification of the secondary electron transport in a track structure simulation has been suggested by Toburen et al. (2010), who have measured the angle-dependent energy spectra of electrons, emitted from a thin layer of amorphous solid water (ASW) upon a …

New Structural Similarity Measure For Image Comparison, Prashan Premaratne, Malin Premaratne

Faculty of Engineering and Information Sciences - Papers: Part A

Subjective quality measures based on Human Visual System for images do not agree well with well-known metrics such as Mean Squared Error and Peak Signal to Noise Ratio. Recently, Structural Similarity Measure (SSIM) has received acclaim due to its ability to produce results on a par with Human Visual System. However, experimental results indicate that noise and blur seriously degrade the performance of the SSIM metric. Furthermore, despite SSIM's popularity, it does not provide adequate insight into how it handles 'structural similarity' of images. We propose a structural similarity measure based on approximation level of a given Discrete Wavelet Decomposition …

A Social Network Model For Understanding Technology Use For Knowledge-Intensive Workers, Kon Shing Kenneth Chung

Faculty of Engineering and Information Sciences - Papers: Part A

This chapter presents a theoretical model based on social network theories and the social influence model for understanding how knowledge professionals utilise technology. In particular, the association between egocentric network properties (structure, position and tie) and information and communication technology (ICT) use of individuals in knowledge-intensive and geographically dispersed settings is explored. A novel triangulation methodology is adopted where in-depth interviews and observation techniques were utilised to develop constructs for the conceptual model which were then vetted by domain-level experts. A reliable and validated social network-based questionnaire survey is also developed to operationalise the model. Results show that task-level ICT …

Development And Validation Of A Concept Inventory For Introductory-Level Climate Change Science, Lorna Jarrett, Brian Ferry, George Takacs

Faculty of Engineering and Information Sciences - Papers: Part A

This paper follows on from Jarrett, Takacs and Ferry (2011) which reported the first stage in development of a high school level concept inventory (CI) for the science of climate change: the climate change concept inventory (CCCI). In order to develop a reliable and valid instrument, it is necessary to follow appropriate procedures. This paper details the process of CI item development; reports statistical results of initial field trials and outlines how these will be used to further refine the CCCI. Item difficulty, discrimination, and point biserial coefficient were calculated for each item. Cronbach's alpha and test-retest data were used …

Design And Development Of Compact Readout Electronics With Silicon Photomultiplier Array For A Compact Imaging Detector, Xiao-Hui Zhang, Yu-Jin Qi, Cui-Lan Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

This work aims at developing compact readout electronics for a compact imaging detector module with silicon photomultiplier (SPM) array. The detector module consists of a LYSO crystal array coupling with a SensL's 4×4 SPM array. A compact multiplexed readout based on a discretized positioning circuit (DPC) was developed to reduce the readout channels from 16 to 4 outputs. Different LYSO crystal arrays of 4×4, 8×8 and 12×12 with pixel sizes of 3.2, 1.6 and 1.0 mm respectively, have been tested with the compact readout board using a 137Cs source. The initial results show that the compact imaging detector module with …

A Soft-In Soft-Out Detection Approach Using Partial Gaussian Approximation, Qinghua Guo, Licai Fang, Defeng (David) Huang, Sven Nordholm

Faculty of Engineering and Information Sciences - Papers: Part A

This paper concerns the implementation of the softin soft-out detector in an iterative detection system. A detection approach is proposed based on the properties of Gaussian functions. In this approach, for the computation of the APP (a posteriori probability) of a concerned symbol, the other symbols are distinguished based on their contributions to the APP of the concerned symbol, and the symbols with less contributions are treated as Gaussian variables to reduce the computational complexity. The exact APP detector and the well-known LMMSE (linear minimum mean square error) detector are two special cases of the proposed detector. Simulation results show …

Chain-Die Forming, Is It A Right Forming Method To Make Structural Parts Of Motor Vehicles With Uhss Material, Shichao Ding, Yuankun Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Reducing the body weight of a motor vehicle is one of the most important research approaches in car manufacturing and steel making industries in order to reduce the pollution caused by motor vehicles. In this approach, ultra-high strength steel (UHSS) is developed by steel makers and has been applied more and more to motor vehicles. The UHSS materials have the required strength, but more or less the material's ductility is sacrificed to achieve this target. High strength materials are difficult to form using conventional forming methods. Forming high strength materials to parts effectively and economically is a high priority. Chain-die …