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- Shi Xue Dou (4)
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- Ah Chung Tsoi (2)
- Dr Guomin Yang (2)
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- Paul F. Eschenfelder (2)
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- Cher Hau Seng (1)
- Dr Mark Freeman (1)
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- Long D Nghiem (1)
Articles 91 - 118 of 118
Full-Text Articles in Science and Technology Studies
Double Space-Time Transmit Diversity For Very High Data Rate Mb-Ofdm Uwb Systems, Ngoc P. Le, Le C. Tran, Farzad Safaei
Double Space-Time Transmit Diversity For Very High Data Rate Mb-Ofdm Uwb Systems, Ngoc P. Le, Le C. Tran, Farzad Safaei
Professor Farzad Safaei
In this paper, we investigate a multiband-orthogonal frequency division multiplexing ultra-wideband (MB-OFDM UWB) system with very high data rates (VHDR) of several gigabits per second (Gbps). We propose a DSTTD-based VHDR MB-OFDM UWB system by incorporating a double space-time transmit diversity (DSTTD) scheme into the conventional MB-OFDM UWB system. At the receiver, an efficient soft-demapper that takes into consideration the noise enhancement due to a zero-forcing equalization is developed. Numerical simulations of the proposed system at a very high data rate of 2.Gbps over the IEEE 802.15.3a channel models are implemented. The simulation results show that this system could achieve …
The Effect Of Different Rotation Patterns On The Revisions Of Trend Estimates, David G. Steel, Craig H. Mclaren
The Effect Of Different Rotation Patterns On The Revisions Of Trend Estimates, David G. Steel, Craig H. Mclaren
Professor David Steel
The X11 and X11ARIMA procedures are widely used to produce seasonally adjusted and trend estimates from time series obtained from sample surveys. The surveys are often based on designs in which there is sample overlap between different periods. The degree of overlap is determined by the pattern of inclusion of selected units over time, i.e., the rotation pattern. An important issue in analysing the series is that trend estimates at the end of the series are revised as estimates for recent periods are added. This article considers the effects of different rotation patterns on the mean squared error of the …
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
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
Professor David Steel
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 …
What Users Do: Sa&D With The Atsa Method, Robert B. K Brown, Ian C. Piper
What Users Do: Sa&D With The Atsa Method, Robert B. K Brown, Ian C. Piper
Dr Ian Piper
Incomplete or inefficient elicitation, comprehension and transmission of client requirements are all sources of information system (IS) failure rates. Requirements may be missed, misunderstood or miscommunicated for the lack of a single, consistent, informing theory. Structured requirements elicitations techniques impose time delays. Cursory techniques can fail to reach any mutual understanding with the stakeholder. Formal methods can fail to cope with non-functional requirements and coder-oriented methods can put the cart before the horse, delivering something other than required. Agile methods can deliver hasty product, cobbled to meet first-cut requirements, perhaps justified by a notion that users cannot reach stable conclusions.
Eliciting And Specifying Requirements For Highly Interactive Systems Using Activity Theory, Robert B. K. Brown, Peter Hyland, Ian C. Piper
Eliciting And Specifying Requirements For Highly Interactive Systems Using Activity Theory, Robert B. K. Brown, Peter Hyland, Ian C. Piper
Dr Ian Piper
The processes of eliciting user requirements and formalising these into specifications are critical for the success of highly interactive systems. These processes are still poorly understood, partly because current methods are usually ad hoc and lack any theoretical basis. A number of researchers have used Activity Theory (AT) to refine these processes and have met with some success. To date, this approach has been more useful explaining the processes post hoc. This positional paper proposes an AT method for requirement elicitation and specification definition. The method is sufficiently prescriptive and well formed that it does not require any detailed understanding …
Specifying System Requirements Using The 5s Method, Robert B. K Brown, Peter Hyland, Ian C. Piper
Specifying System Requirements Using The 5s Method, Robert B. K Brown, Peter Hyland, Ian C. Piper
Dr Ian Piper
The 5S Method takes an Activity Theory approach to stakeholder elicitation. We interview stakeholders and build up a network of Activities according to Activity Theory precepts. These Activities are hierarchically decomposed into the smaller units of Action and Operation. This comprises a useful conceptual map of the human motivations and dependencies prior to insertion of the new computer based system. To identify and describe such a potential computer system, we analyse and identify linkages between the Activities and assemble a list of those which could usefully pass through such a computer system. Design decisions are driven and evaluated by reference …
(Strong) Multi-Designated Verifiers Signatures Secure Against Rogue Key Attack, Yunmei Zhang, Man Ho Allen Au, Guomin Yang, Willy Susilo
(Strong) Multi-Designated Verifiers Signatures Secure Against Rogue Key Attack, Yunmei Zhang, Man Ho Allen Au, Guomin Yang, Willy Susilo
Dr Guomin Yang
Designated verifier signatures (DVS) allow a signer to create a signature whose validity can only be verified by a specific entity chosen by the signer. In addition, the chosen entity, known as the designated verifier, cannot convince any body that the signature is created by the signer. Multi-designated verifiers signatures (MDVS) are a natural extension of DVS in which the signer can choose multiple designated verifiers. DVS and MDVS are useful primitives in electronic voting and contract signing. In this paper, we investigate various aspects of MDVS and make two contributions. Firstly, we revisit the notion of unforgeability under rogue …
The Magnetocaloric Effect And Critical Behaviour Of The Mn0.94ti0.06coge Alloy, P Shamba, Jianli Wang, J C. Debnath, S J. Kennedy, Rong Zeng, M F Md Din, F Hong, Z X. Cheng, A J. Studer, S X. Dou
The Magnetocaloric Effect And Critical Behaviour Of The Mn0.94ti0.06coge Alloy, P Shamba, Jianli Wang, J C. Debnath, S J. Kennedy, Rong Zeng, M F Md Din, F Hong, Z X. Cheng, A J. Studer, S X. Dou
Shi Xue Dou
Structural, magnetic and magnetocaloric properties of the Mn0.94Ti0.06CoGe alloy have been investigated using x-ray diffraction, DC magnetization and neutron diffraction measurements. Two phase transitions have been detected, at T-str = 235 K and T-C = 270 K. A giant magnetocaloric effect has been obtained at around Tstr associated with a structural phase transition from the low temperature orthorhombic TiNiSi-type structure to the high temperature hexagonal Ni2In-type structure, which is confirmed by neutron study. In the vicinity of the structural transition, at T-str, the magnetic entropy change, -Delta S-M reached a maximum value of 14.8 J kg(-1) K-1 under a magnetic …
Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou
Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou
Shi Xue Dou
Electron-phonon coupling strength was studied in graphene-MgB2 composites to explore the possibilities for a higher superconducting transition temperature (Tc). For the first time in the experimental work on MgB2, the Raman active E2g mode was split into two parts: a softened mode corresponding to tensile strain and a hardened mode attributed to the carbon substitution effect. The tensile strain effect is suggested to improve Tc of graphene-MgB2 composites because it increases the electron-phonon coupling strength of MgB2.
Effect Of Gallium Doping And Ball Milling Process On The Thermoelectric Performance Of N-Type Zno, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Effect Of Gallium Doping And Ball Milling Process On The Thermoelectric Performance Of N-Type Zno, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Shi Xue Dou
We report a systematic investigation of the thermoelectric properties of n-type Ga-doped ZnO synthesized using different ball milling conditions. Samples fabricated by the high-energy ball milling resulted in a highly dense layered structure with randomly distributed voids. These samples measured the lowest room temperature thermal conductivity, i.e., 27 W/mK due to increased phonon scattering. Furthermore, the Ga:ZnO system showed a metal–semiconductor transition above 300 K with transition temperature decreasing with increasing doping level. Measurement of the activation energy revealed the presence of one donor level around 3.9–7.8 meV and a deeper donor level around 15.4–18.1 meV below the conduction band …
Enhancement Of The Refrigerant Capacity In Low Level Boron Doped La0.8gd0.2fe11.4si1.6, P Shamba, R Zeng, Jianli Wang, S J. Campbell, S X. Dou
Enhancement Of The Refrigerant Capacity In Low Level Boron Doped La0.8gd0.2fe11.4si1.6, P Shamba, R Zeng, Jianli Wang, S J. Campbell, S X. Dou
Shi Xue Dou
The effects of boron doping on the itinerant-electron metamagnetic (IEM) transition and the magnetocaloric effects (MCEs) in the cubic NaZn13-type La0.8Gd0.2Fe11.4Si1.6 compound have been investigated. The Curie temperature, TC, of La0.8Gd0.2Fe11.4Si1.6Bx compounds with x=0, 0.03, 0.06, 0.2 and 0.3 was found to increase from 200 K to 222 K with increase in boron doping, x. The maximum values of the isothermal magnetic entropy change, ΔSM, (derived using the Maxwell relation for a field change ΔB=0-5 T) in La0.8Gd0.2Fe11.4Si1.6Bx with x=0, 0.03, 0.06, 0.2 and 0.3 are 14.8, 16, 15, 7.5 and 6.6 J kg−1 K−1 respectively, with corresponding values of …
Segmentations Of Through-The-Wall Radar Images, C H. Seng, M G. Amin, F Ahmad, A Bouzerdoum
Segmentations Of Through-The-Wall Radar Images, C H. Seng, M G. Amin, F Ahmad, A Bouzerdoum
Cher Hau Seng
In this paper, we examine the use of image segmentation approaches for target detection in TWRI. The betweenclass variance thresholding, entropy-based segmentation, and Kmeans clustering are applied to segment target and clutter regions. Real 2D polarimetric images are used to demonstrate that simple histogram-based segmentation methods produce either comparable or improved performance over the Likelihood Ratio Tests (LRT) detector. Specifically, the results show that, for the cases considered, the entropy-based segmentation outperforms the other image segmentation methods and the LRT detector.
Development Of A Dc-Lsnd Welding Process For Gmaw On Dh-36 Steel, Raymond Holder, Nathan Larkin, Huijun Li, Lenka Kuzmikova, Zengxi Pan, John Norrish
Development Of A Dc-Lsnd Welding Process For Gmaw On Dh-36 Steel, Raymond Holder, Nathan Larkin, Huijun Li, Lenka Kuzmikova, Zengxi Pan, John Norrish
Nathan Larkin
Weld induced distortion correction is a major cost within the shipbuilding industry. This paper investigates the use of an active cooling process known as Dynamically Controlled - Low Stress No Distortion (DC-LSND) Welding on DH-36 steel. Thermal profiles are obtained and distortion measurements are also achieved. Results show that the application of a localised cryogenic cooling source trailing the welding arc can significantly reduce weld induced distortion using the GMAW process. The effect of forced cooling on the weld microstructure is also observed.
Optimization Of Welding Parameters For Repairing Nial Bronze Components, Huijun Li, Daniel Grudgings, Nathan P. Larkin, John Norrish, Mark Callaghan, Lenka Kuzmikova
Optimization Of Welding Parameters For Repairing Nial Bronze Components, Huijun Li, Daniel Grudgings, Nathan P. Larkin, John Norrish, Mark Callaghan, Lenka Kuzmikova
Nathan Larkin
The objective of this study is to determine an optimal welding procedure that can be implemented to repair damaged Nickel Aluminium Bronze (NAB) components. NAB is commonly used in marine applications where components are subject to a constant corrosive environment and high stresses. Research into ideal NAB microstructure for a marine application, was performed in order to gain a baseline for experimental analysis of potential welding procedures. The results indicated that the welding repair can be performed with a wide range of heat input. The effect of post-weld heat treatment (PWHT) on the microstructure and mechanical properties in the heat …
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
Nathan Larkin
In this study, the feasibility of hybrid laser-gas metal arc welding process for replacement of conventional flux-cored arc welding procedure for welding high strength quenched and tempered steel was investigated. Experimental work focused on optimisation of process parameters to produce joint with desired properties. Hardness of the weld heat affected zone produced by both processes has been measured. Productivity and cost effectiveness of both processes were compared. It was concluded that hybrid laser-gas metal arc welding process is suitable for welding high strength quenched and tempered steel.
Offline Programming For Short Batch Robotic Welding, Nathan Larkin, Aleksandar Milojevic, Zengxi Pan, Joseph Polden, John Norrish
Offline Programming For Short Batch Robotic Welding, Nathan Larkin, Aleksandar Milojevic, Zengxi Pan, Joseph Polden, John Norrish
Nathan Larkin
Robotics based automation has many advantages over both manual operation and dedicated hard automation. In practice however the robot programming overhead and high cost of dedicated jigging are serious impediments to its use for short production runs. Offline programming packages offer an attractive alternative to reduce programming time and robot down time, however many of the available packages are fairly complex and treat the geometric programming and welding operation separately. The paper will describe the development of alternative approaches and the evaluation of an integrated offline robotic welding package (RinasWeld) which addresses these issues and makes low volume robotic welding …
Influence Of Formulated Chemical Cleaning Reagents On The Surface Properties And Separation Efficiency Of Nanofiltration Membranes, Alexander Simon, William E. Price, Long D. Nghiem
Influence Of Formulated Chemical Cleaning Reagents On The Surface Properties And Separation Efficiency Of Nanofiltration Membranes, Alexander Simon, William E. Price, Long D. Nghiem
Long D Nghiem
This study investigated the impact of two caustic and one acidic cleaning formulations (namely MC11, PC98, and MC3, respectively) on the properties and separation efficiency of three different nanofiltration (NF) membranes (namely NF270, NF90 and TFC-SR100). Overall, the impact of chemical cleaning on surface properties and rejection was membrane and cleaning reagent specific. It was driven mostly by conformational changes of the membrane polymeric active skin layer in response to an extreme caustic or acidic environment and to a certain extent by the adsorption of cleaning additives (e.g., surfactants and chelating reagents). The influence of chemical cleaning on the membrane …
Influence Of Formulated Chemical Cleaning Reagents On The Surface Properties And Separation Efficiency Of Nanofiltration Membranes, Alexander Simon, William E. Price, Long D. Nghiem
Influence Of Formulated Chemical Cleaning Reagents On The Surface Properties And Separation Efficiency Of Nanofiltration Membranes, Alexander Simon, William E. Price, Long D. Nghiem
William E. Price
This study investigated the impact of two caustic and one acidic cleaning formulations (namely MC11, PC98, and MC3, respectively) on the properties and separation efficiency of three different nanofiltration (NF) membranes (namely NF270, NF90 and TFC-SR100). Overall, the impact of chemical cleaning on surface properties and rejection was membrane and cleaning reagent specific. It was driven mostly by conformational changes of the membrane polymeric active skin layer in response to an extreme caustic or acidic environment and to a certain extent by the adsorption of cleaning additives (e.g., surfactants and chelating reagents). The influence of chemical cleaning on the membrane …
Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera
Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera
Dr Philip Ciufo
In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …
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
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
Dr Philip Ciufo
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 …
Impact Of Mains Connected Three-Phase Induction Motor Loading Levels On Network Voltage Unbalance Attenuation, Upuli Jayatunga, Sarath Perera, Philip Ciufo
Impact Of Mains Connected Three-Phase Induction Motor Loading Levels On Network Voltage Unbalance Attenuation, Upuli Jayatunga, Sarath Perera, Philip Ciufo
Dr Philip Ciufo
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 …
Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo
Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo
Dr Philip Ciufo
Embedded generators such as wind generators can produce observable voltage fluctuations during variable wind conditions hence flicker. The flicker produced by such intermittent and fluctuating generating sources can propagate to other parts of the distribution network while creating power quality issues in distribution feeders. This study presents a flicker emission analysis for a doubly-fed induction generator (DFIG) based wind farm and investigate the pertinent factors which influence flicker propagation and attenuation in distribution feeders. Study has shown that voltage fluctuations are significantly influenced by the attenuation characteristics of various load types (i.e. constant power, impedance and current loads) connected to …
Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang
Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang
Professor Weihua Li
In this paper, an integrated vehicle seat and sus pension control strategy for a quarter car with driver model is proposed to improve suspension performance on driver ride comfort. An integrated seat and suspension model that includes a quarter-car suspension, a seat suspension, and a 4-degree-of freedom (DOM) driver body model is presented first. This in1 tegrated model provides a platform to evaluate ride comfort 1performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car suspensions. Based on the integrated model, an H∞ state feedback controller is designed …
New Peril + Old Promises = Bad Results, Paul Eschenfelder
New Peril + Old Promises = Bad Results, Paul Eschenfelder
Paul F. Eschenfelder
No abstract provided.
Erau Spring 2013 Newsletter, Paul Eschenfelder
Erau Spring 2013 Newsletter, Paul Eschenfelder
Paul F. Eschenfelder
No abstract provided.
Location And Tracking Of Mobile Devices: Überveillance Stalks The Streets, Katina Michael, Roger Clarke
Location And Tracking Of Mobile Devices: Überveillance Stalks The Streets, Katina Michael, Roger Clarke
Professor Katina Michael
During the last decade, location-tracking and monitoring applications have proliferated, in mobile cellular and wireless data networks, and through self-reporting by applications running in smartphones that are equipped with onboard global positioning system (GPS) chipsets. It is now possible to locate a smartphone-user's location not merely to a cell, but to a small area within it. Innovators have been quick to capitalise on these location-based technologies for commercial purposes, and have gained access to a great deal of sensitive personal data in the process. In addition, law enforcement utilise these technologies, can do so inexpensively and hence can track many …
Towards A Conceptual Model Of User Acceptance Of Location-Based Emergency Services, Anas Aloudat, Katina Michael
Towards A Conceptual Model Of User Acceptance Of Location-Based Emergency Services, Anas Aloudat, Katina Michael
Professor Katina Michael
This paper investigates the introduction of location-based services by government as part of an all-hazards approach to modern emergency management solutions. Its main contribution is in exploring the determinants of an individual’s acceptance or rejection of location services. The authors put forward a conceptual model to better predict why an individual would accept or reject such services, especially with respect to emergencies. While it may be posited by government agencies that individuals would unanimously wish to accept life-saving and life-sustaining location services for their well-being, this view remains untested. The theorised determinants include: visibility of the service solution, perceived service …
The Future Prospects Of Embedded Microchips In Humans As Unique Identifiers: The Risks Versus The Rewards, Katina Michael, M.G. Michael
The Future Prospects Of Embedded Microchips In Humans As Unique Identifiers: The Risks Versus The Rewards, Katina Michael, M.G. Michael
Professor Katina Michael
Microchip implants for humans are not new. Placing heart pacemakers in humans for prosthesis is now considered a straightforward procedure. In more recent times we have begun to use brain pacemakers for therapeutic purposes to combat illnesses such as epilepsy, Parkinson’s Disease, and severe depression. Microchips are even being placed inside prosthetic knees and hips during restorative procedures to help in the gathering of post-operative analytics that can aid rehabilitation further. While medical innovations that utilise microchips abound, over the last decade we have begun to see the potential use of microchip implants for non-medical devices in humans, namely for …