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Full-Text Articles in Social and Behavioral Sciences

Behaviour Of Clay-Fouled Ballast Under Drained Triaxial Testing, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Shrawan Nimbalkar, Cholachat Rujikiatkamjorn Jan 2013

Behaviour Of Clay-Fouled Ballast Under Drained Triaxial Testing, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Shrawan Nimbalkar, Cholachat Rujikiatkamjorn

Faculty of Engineering and Information Sciences - Papers: Part A

Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail …


Suitability Assessment Framework Of Agent-Based Software Architectures, Ghassan Beydoun, Graham Low, Paul Bogg Jan 2013

Suitability Assessment Framework Of Agent-Based Software Architectures, Ghassan Beydoun, Graham Low, Paul Bogg

Faculty of Engineering and Information Sciences - Papers: Part A

Context: A common distributed intelligent system architecture is Multi Agent Systems (MASs). Creating systems with this architecture has been recently supported by Agent Oriented Software Engineering (AOSE) methodologies. But two questions remain: how do we determine the suitability of a MAS implementation for a particular problem? And can this be determined without AOSE expertise? Objective: Given the relatively small number of software engineers that are AOSE experts, many problems that could be better solved with a MAS system are solved using more commonly known but not necessarily as suitable development approaches (e.g. object-oriented). The paper aims to empower software engineers, …


Fully Secure Hidden Vector Encryption Under Standard Assumptions, Jong Hwan Park, Kwangsu Lee, Willy Susilo, Dong Hoon Lee Jan 2013

Fully Secure Hidden Vector Encryption Under Standard Assumptions, Jong Hwan Park, Kwangsu Lee, Willy Susilo, Dong Hoon Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Hidden Vector Encryption (HVE) is a special type of predicate encryption that can support conjunctive equality and range searches on encrypted data. All previous HVE schemes were proven to be either selectively secure or weakly attribute-hiding. In this paper, we first construct a new HVE scheme that is fully secure under standard assumptions. Our HVE scheme, which is based on bilinear maps (pairings), provides efficiency advantages in that it requires O(1)-sized private keys and O(1) pairing computations for decryption, regardless of both the number of conjunctives and the dimension of vectors. To achieve our goal, we develop a novel technique …


Efficient Linkable And/Or Threshold Ring Signature Without Random Oracles, Tsz Hon Yuen, Joseph K. Liu, Man Ho Au, Willy Susilo, Jianying Zhou Jan 2013

Efficient Linkable And/Or Threshold Ring Signature Without Random Oracles, Tsz Hon Yuen, Joseph K. Liu, Man Ho Au, Willy Susilo, Jianying Zhou

Faculty of Engineering and Information Sciences - Papers: Part A

Linkable ring signatures have found many attractive applications. One of the recent important extensions is a linkable threshold ring signature (LTRS) scheme. Unfortunately, the existing LTRS schemes are only secure in the random oracle model (ROM). In this paper, we make the following contributions. First, we construct the first LTRS scheme that is secure without requiring the ROM. Further, we enhance the security of a threshold ring signature (for both linkable or non-linkable) by providing a stronger definition of anonymity. This strengthened notion makes threshold ring signature schemes more suitable in real life. Finally, we provide efficient schemes that outperform …


Estimating The Rate Of Erosion Of A Silty Sand Treated With Lignosulfonate, Buddhima Indraratna, Rasika Athukorala, Jayan Vinod Jan 2013

Estimating The Rate Of Erosion Of A Silty Sand Treated With Lignosulfonate, Buddhima Indraratna, Rasika Athukorala, Jayan Vinod

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes a theoretical model to capture the rate of erosion of a silty sand based on the principle of conservation of energy. Erosion is considered to begin when the interparticle bonds between grains are broken by hydrodynamic stresses exerted on the soil particles. These detached particles are then suspended and transported by the flow of eroding fluid. It is further assumed that once the particles are fully suspended and have reached the flow velocity, resettlement does not take place. Stabilization of soil particles because of lignosulfonate (LS) treatment is represented by the increased strain energy required to break …


Continuous Manipulation And Separation Of Particles Using Combined Obstacle-And Curvature-Induced Direct Current Dielectrophoresis, Ming Li, Shunbo Li, Weihua Li, Weijia Wen, Gursel Alici Jan 2013

Continuous Manipulation And Separation Of Particles Using Combined Obstacle-And Curvature-Induced Direct Current Dielectrophoresis, Ming Li, Shunbo Li, Weihua Li, Weijia Wen, Gursel Alici

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a novel dielectrophoresis-based microfluidic device incorporating round hurdles within an S-shaped microchannel for continuous manipulation and separation of microparticles. Local nonuniform electric fields are generated due to the combined effects of obstacle and curvature, which in turn induce negative dielectrophoresis forces exerting on the particle that transport throughout the microchannel electrokinetically. Experiments were conducted to demonstrate the controlled trajectories of fix-sized (i.e. 10 or 15x μm) polystyrene particles, and size-dependent separation of 10 and 15 μm particles by adjusting the applied voltages at the inlet and outlets. Numerical simulations were also performed to predict the particle trajectories, …


Fabrication And Characterization Of Pdms Based Magnetorheological Elastomers, Weihua Li, Masami Nakano Jan 2013

Fabrication And Characterization Of Pdms Based Magnetorheological Elastomers, Weihua Li, Masami Nakano

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the fabrication and characterization of a new magnetorheological elastomer (MRE) by using polydimethylsiloxane (PDMS) as a matrix. The base and curing agent of PDMS with a weight ratio of 10:1 were mixed first as the carrying matrix, and then carbonyl iron particles were added to the matrix and stirred sufficiently. The final mixture was placed in a vacuum chamber to eliminate bubbles for 30 min and was moulded later to form membranes of 1 mm thickness. A total of four PDMS based MRE samples, with different weight fractions of 60%, 70%, 80%, and 90%, were fabricated. Their …


Light Reflection Is Nonlinear Optimization, Jiakun Liu Jan 2013

Light Reflection Is Nonlinear Optimization, Jiakun Liu

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we show that the near field reflector problem is a nonlinear optimization problem. From the corresponding functional and constraint function, we derive the Monge-Ampère type equation for such a problem.


A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto Jan 2013

A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage regulation (VR) is a procedure to keep voltages in a distribution network (DN) within normal limits. Conven- tionally, a voltage regulator can read voltage levels from pre- dened measures, and regulate the voltages. However, due to lacking of a distributed generator's (DG) information, the unexpected electricity from a DG will mislead readings on voltages levels, so as to disturb the VR in a DN. Adjust- ing a DG's reactive power output is an alternative way for VR. However, because of limited penetration levels, DGs need to collaborate with other devices in order to provide an eective voltage regulation. Therefore, …


Discovery Of Communications Patterns By The Use Of Intelligent Reasoning, J Fulcher, Minjie Zhang, Q Bai, F Ren Jan 2013

Discovery Of Communications Patterns By The Use Of Intelligent Reasoning, J Fulcher, Minjie Zhang, Q Bai, F Ren

Faculty of Engineering and Information Sciences - Papers: Part A

An agent-based model of communications traffic generated within a social network is described, which caters for various knowledge discovery techniques to be used in order to extract 'interesting' temporal patterns contained within anomalous data records. Attendant Java-based software — NetShow — is presented which enables analysis and display of static network configuration, links between network nodes, and correlations between the traffic passing through nominated nodes. In addition, display of network dynamics is facilitated via the incorporation of swarm techniques. Related issues of 'similarity', 'familiarity' and 'contact lists' are discussed within the context of Social Network Analysis and Link Mining. Finally, …


Removal Of N-Nitrosamines By An Aerobic Membrane Bioreactor, Kaushalya C. Wijekoon, Takahiro Fujioka, James A. Mcdonald, Stuart J. Khan, Faisal I. Hai, William E. Price, Long D. Nghiem Jan 2013

Removal Of N-Nitrosamines By An Aerobic Membrane Bioreactor, Kaushalya C. Wijekoon, Takahiro Fujioka, James A. Mcdonald, Stuart J. Khan, Faisal I. Hai, William E. Price, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

This study investigated the fate of eight N-nitrosamines during membrane bioreactor (MBR) treatment. The results suggest that biodegradation is mainly responsible for the removal of N-nitrosamines during MBR treatment. Other removal mechanisms were insignificant (e.g. adsorption to sludge) or not expected (e.g. photolysis and volatilization) given the experimental conditions and physicochemical properties of the N-nitrosamines studied here. N-nitrosamine removal efficiencies were from 24% to 94%, depending on their molecular properties. High removal of N-nitrosamines such as N-nitrosodimethylamine and N-nitrosodiethylamine could be explained by the presence of strong electron donating functional groups (EDG) in their structure. In contrast, N-nitrosomorpholine possessing the …


A Study On The Suitability Of Cable Models To Simulate Switching Transients In A 132 Kv Underground Cable, Muhamad Zalani Daud, P Ciufo, S Perera Jan 2013

A Study On The Suitability Of Cable Models To Simulate Switching Transients In A 132 Kv Underground Cable, Muhamad Zalani Daud, P Ciufo, S Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Switching transients resulting from the energisation of high voltage cable systems may have a significant effect on both the cables being switched as well as the power system components in the vicinity. The impacts of these transients on such cables are measured based on the stress arising as a result of the voltage and current peaks and the frequency of oscillatory transients. These quantities are typically obtained from a simulation by using a suitable cable model, normally with the capability to predict the transient behaviour in the range up to several 10 kHz. To obtain a cable model that enables …


A Density- And Stress-Dependent Elasto-Plastic Model For Sands Subjected To Monotonic Undrained Torsional Shear Loading, G Chiaro, J Koseki, L. I Nalin De Silva Jan 2013

A Density- And Stress-Dependent Elasto-Plastic Model For Sands Subjected To Monotonic Undrained Torsional Shear Loading, G Chiaro, J Koseki, L. I Nalin De Silva

Faculty of Engineering and Information Sciences - Papers: Part A

A density- and stress-dependent elasto-plastic model for saturated sands undergoing monotonic undrained torsional shear loading is presented in this paper. The model is developed under an extended general hyperbolic equation (GHE) approach, in which the void ratio and stress level dependence upon stress-strain response of sand is incorporated. Most importantly, a state-dependent stress-dilatancy relationship is introduced to account for the effect of density on the stress ratio. Such a stress-dilatancy relation is used for modeling the excess pore water pressure generation in undrained shear conditions as the mirror effect of volumetric change in drained shear conditions. In this paper, details …


Ropes Eye Plaque Dosimetry: Commissioning And Verification Of An Ophthalmic Brachytherapy Treatment Planning System, J Poder, N Annabell, M Geso, M Alqathami, S Corde Jan 2013

Ropes Eye Plaque Dosimetry: Commissioning And Verification Of An Ophthalmic Brachytherapy Treatment Planning System, J Poder, N Annabell, M Geso, M Alqathami, S Corde

Faculty of Engineering and Information Sciences - Papers: Part A

In this study, the Plaque SimulatorTM eye plaque brachytherapy planning system was commissioned for ROPES eye plaques and Amersham Health model 6711 Iodine 125 seeds, using TG43-UI data. The brachytherapy module of the RADCALC® independent checking program was configured to allow verification of the accuracy of the dose calculated by Plaque SimulatorTM. Central axis depth dose distributions were compared and observed to agree to within 2% for all ROPES plaque models and depths of interest. Experimental measurements were performed with a customized PRESAGEm 3-D type dosimeter to validate the calculated depth dose distributions. Preliminary results have shown the effect of …


Public Key Encryption With Keyword Search Secure Against Keyword Guessing Attacks Without Random Oracle, Liming Fang, Willy Susilo, Chunpeng Ge, Jiandong Wang Jan 2013

Public Key Encryption With Keyword Search Secure Against Keyword Guessing Attacks Without Random Oracle, Liming Fang, Willy Susilo, Chunpeng Ge, Jiandong Wang

Faculty of Engineering and Information Sciences - Papers: Part A

The notion of public key encryption with keyword search (PEKS) was put forth by Boneh et al. to enable a server to search from a collection of encrypted emails given a “trapdoor” (i.e., an encrypted keyword) provided by the receiver. The nice property in this scheme allows the server to search for a keyword, given the trapdoor. Hence, the verifier can merely use an untrusted server, which makes this notion very practical. Following Boneh et al.’s work, there have been subsequent works that have been proposed to enhance this notion. Two important notions include the so-called keyword guessing attack and …


Development Of Safe Optimized Welding Procedures For High Strength Q&T Steel Welded With Austenitic Consumables, Lenka Kuzmikova, Huijun Li, John Norrish, Zengxi Stephen Pan, Nathan Larkin Jan 2013

Development Of Safe Optimized Welding Procedures For High Strength Q&T Steel Welded With Austenitic Consumables, Lenka Kuzmikova, Huijun Li, John Norrish, Zengxi Stephen Pan, Nathan Larkin

Faculty of Engineering and Information Sciences - Papers: Part A

High strength quenched and tempered (Q&T) steels offer obvious economic benefits originating from their advantageous strength to price and weight ratios. These steels are usually welded using ferritic consumables and for this combination the risk of hydrogen assisted cold cracking (HACC) is high. The use of austenitic stainless steel (ASS) consumables has great potential to significantly improve this issue. Yet, there are no guidelines for determination of safe level of preheat for welding ferritic steels with ASS consumables. For this reason manufacturers adopt this parameter from procedures developed for conventional ferritic consumables thus significantly limiting the benefits ASS consumables are …


Quantitative Model For Tunable Microstructure In Magnetic Fept Thin Films By Pulsed Laser Deposition, Igor A. Golovchanskiy, Sergey A. Fedoseev, Alexey V. Pan Jan 2013

Quantitative Model For Tunable Microstructure In Magnetic Fept Thin Films By Pulsed Laser Deposition, Igor A. Golovchanskiy, Sergey A. Fedoseev, Alexey V. Pan

Faculty of Engineering and Information Sciences - Papers: Part A

Pulsed laser deposition (PLD) is employed to fabricate FePt L10 thin films from elemental targets. Dramatic structure variations are obtained by varying the laser frequency while keeping the thickness of the films constant. A new theoretical model based on the mean field approach is proposed, which quantitatively describes the structural changes obtained experimentally. The experiment and the model exhibit the opposite growth development to the trend reported for the modulated flux in the literature. The new model considers different growth rates in the lateral and transverse directions due to different responses of the normal and tangential film surfaces being deposited …


Cost And Time Aware Ant Colony Algorithm For Data Replica In Alpha Magnetic Spectrometer Experiment, Lijuan Wang, Junzhou Luo, Jun Shen, Fang Dong Jan 2013

Cost And Time Aware Ant Colony Algorithm For Data Replica In Alpha Magnetic Spectrometer Experiment, Lijuan Wang, Junzhou Luo, Jun Shen, Fang Dong

Faculty of Engineering and Information Sciences - Papers: Part A

Huge collections of data have been created in recent years. Cloud computing provides a way to enable massive amounts of data to work together as data-intensive services. Considering Big Data and the cloud together, which is a practical and economical way to deal with Big Data, will accelerate the availability and acceptability of analysis of the data. Providing an efficient mechanism for optimized data-intensive services will become critical to meet the expected growth in demand. Because the competition is an extremely important factor in the marketplace, the cost model for data-intensive service provision is the key to provide a sustainable …


Alternative Al Production Methods: Part 1 - A Review Of Indirect Carbothermal Routes, M A. Rhamdhani, M A. Dewan, G A. Brooks, B J. Monaghan, L Prentice Jan 2013

Alternative Al Production Methods: Part 1 - A Review Of Indirect Carbothermal Routes, M A. Rhamdhani, M A. Dewan, G A. Brooks, B J. Monaghan, L Prentice

Faculty of Engineering and Information Sciences - Papers: Part A

The production of Al from its ores at present relies on the Bayer (alumina production) and the Hall- Heroult (Al production) process. The cost associated with alumina production and apparent disadvantages of the Hall-Heroult process have led to intensive research to find alternative routes for Al production. The direct carbothermal reduction process has been thoroughly investigated as an alternative technique. Another alternative includes the indirect carbothermal reduction route where alumina (or aluminous ores) is first reduced to intermediate Al compounds before reduced further to Al. The present study reviews and provides systematic thermodynamic analyses of alternative Al production routes. In …


From Theory To Practice In Rail Geotechnology, B Indraratna, Sanjay Nimbalkar, N Tennakoon, Q D. Sun Jan 2013

From Theory To Practice In Rail Geotechnology, B Indraratna, Sanjay Nimbalkar, N Tennakoon, Q D. Sun

Faculty of Engineering and Information Sciences - Papers: Part A

In recent times the increase in axle loads and train speeds have posed serious geotechnical issues with ballasted railway tracks, both in Australia and the world. The large deformations and degradation of ballast under cyclic and impact loads, and the low bearing capacity of compacted ballast and impaired drainage often exacerbate track maintenance. In recent times in Australia, geosynthetics have been trialed in ballasted tracks constructed on soft and saturated formations to help improve stability and longevity. Comprehensive field studies on instrumented tracks at Bulli (near Wollongong) and Singleton (near Newcastle) supported by RailCorp and ARTC, were carried out to …


Comparison Between Sequential And Simultaneous Application Of Activated Carbon With Membrane Bioreactor For Trace Organic Contaminant Removal, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, Long D. Nghiem, William E. Price, Wenshan Guo, Huu H. Ngo, Kuo-Lun Tung Jan 2013

Comparison Between Sequential And Simultaneous Application Of Activated Carbon With Membrane Bioreactor For Trace Organic Contaminant Removal, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, Long D. Nghiem, William E. Price, Wenshan Guo, Huu H. Ngo, Kuo-Lun Tung

Faculty of Engineering and Information Sciences - Papers: Part A

The removal efficiency of 22 selected trace organic contaminants by sequential application of granular activated carbon (GAC) and simultaneous application of powdered activated carbon (PAC) with membrane bioreactor (MBR) was compared in this study. Both sequential application of GAC following MBR treatment (MBR–GAC) and simultaneous application of PAC within MBR (PAC–MBR) achieved improved removal (over 95%) of seven hydrophilic and biologically persistent compounds, which were less efficiently removed by MBR-only treatment (negligible to 70%). However, gradual breakthrough of these compounds occurred over an extended operation period. Charged compounds, particularly, fenoprop and diclofenac, demonstrated the fastest breakthrough (complete and 50–70%, in …


A New Approach To Harmonic Allocation For Medium-Voltage Installations, Victor J. Gosbell, R A. Barr Jan 2013

A New Approach To Harmonic Allocation For Medium-Voltage Installations, Victor J. Gosbell, R A. Barr

Faculty of Engineering and Information Sciences - Papers: Part A

Distributors need to allocate a maximum allowed level of harmonic current to medium-voltage customers to keep voltage distortion acceptable. Tlie paper describes a new approach, based on the concept of voltage droop, requiring much less calculation and data than required by the present approach based on an IEC technical report. The discrepancy between the new method and the present is studied by comparing some carefully selected scenarios. It is shown that the proposed method gives results within 20% of the standards-based approach which makes it a very attractive alternative for harmonic allocation. © Institution of Engineers Australia, 2013.


Net Section Tension Capacity Of Cold-Reduced Sheet Steel Angle Braces Bolted At One Leg, Lip H. Teh, Benoit P. Gilbert Jan 2013

Net Section Tension Capacity Of Cold-Reduced Sheet Steel Angle Braces Bolted At One Leg, Lip H. Teh, Benoit P. Gilbert

Faculty of Engineering and Information Sciences - Papers: Part A

This paper examines the accuracy of equations specified by the North American and Australasian steel structures codes for determining the net section tension capacity of a cold-formed steel angle brace bolted at one leg. The configurations tested in the laboratory include single equal angle, single unequal angle bolted at the wider leg, single unequal angle bolted at the narrow leg, double angles, and alternate angles. The steel materials used in the experiment are among those with the lowest ductility for which nominal tensile strength is permitted by cold-formed steel design codes to be fully utilized in structural design calculations. Based …


Bayesian Learning And Predictability In A Stochastic Nonlinear Dynamical Model, John Parslow, Noel Cressie, Edward P. Campbell, Emlyn Jones, Lawrence Murray Jan 2013

Bayesian Learning And Predictability In A Stochastic Nonlinear Dynamical Model, John Parslow, Noel Cressie, Edward P. Campbell, Emlyn Jones, Lawrence Murray

Faculty of Engineering and Information Sciences - Papers: Part A

Bayesian inference methods are applied within a Bayesian hierarchical modelling framework to the problems of joint state and parameter estimation, and of state forecasting. We explore and demonstrate the ideas in the context of a simple nonlinear marine biogeochemical model. A novel approach is proposed to the formulation of the stochastic process model, in which ecophysiological properties of plankton communities are represented by autoregressive stochastic processes. This approach captures the effects of changes in plankton communities over time, and it allows the incorporation of literature metadata on individual species into prior distributions for process model parameters. The approach is applied …


Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera Jan 2013

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 Jan 2013

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 Jan 2013

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 Jan 2013

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 Jan 2013

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 Jan 2013

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 …