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Full-Text Articles in Engineering
A Simulation-Based Decision Support System To Model Complex Demand Driven Heathcare Facilities, Amr Arisha, Michael Thorwarth
A Simulation-Based Decision Support System To Model Complex Demand Driven Heathcare Facilities, Amr Arisha, Michael Thorwarth
Conference papers
Simulating healthcare processes is a sophisticated endeavor. Treatment processes and patient arrival patterns differ significantly in their statistical attributes and implicate a high degree of variability. In addition, there are several types of interconnected processes of medical staff involved that accompany a patient’s journey through the healthcare facility. Replicating this behavior with process flow models in a discrete event simulation model is highly complex and therefore difficult to create while maintaining a high degree of precision. A framework is thus introduced which delivers an algorithm that allows to implement Multiple Participant Pathway Modeling (MPPM) under the consideration of Flexible Resource …
Assembly Time Modeling Through Connective Complexity Metrics, James L. Mathieson, Bradley A. Wallace, Joshua D. Summers
Assembly Time Modeling Through Connective Complexity Metrics, James L. Mathieson, Bradley A. Wallace, Joshua D. Summers
All CEDAR Publications
This paper presents an approach for the development of surrogate models predicting the assembly time of a system based on complexity metrics of the physical system architecture when detailed geometric information is unavailable. A convention for modelling physical architecture is presented, followed by a sample of 10 analysed systems used for training and three systems used for validation. These systems are evaluated on complexity metrics developed from graph theoretic measures. An example model is developed based on a series of regressions of trends observed within the sample data. This is validated against the systems that are not used to develop …
The Implementation Of A Visco-Hyperelastic Numerical Material Model For Simulating The Behaviour Of Polymer Foam Materials, Conor Briody, Barry Duignan, Stephen Jerrams, John Tiernan
The Implementation Of A Visco-Hyperelastic Numerical Material Model For Simulating The Behaviour Of Polymer Foam Materials, Conor Briody, Barry Duignan, Stephen Jerrams, John Tiernan
Articles
Polyurethane foam has been in use for some time in wheelchair seating systems as it offers good pressure relieving capabilities in most cases. However, little characterisation work has gone into seating foam materials by comparison with conventional elastomeric materials. Accurate material models could allow better prediction of foam in-service behaviour, which could potentially improve seating design practises. The objective of this work was to develop an approach for the validation of hyperelastic and viscoelastic material model parameters used to simulate polyurethane foam behaviour. Material parameters were identified from relevant test procedures and implemented in a Finite Element simulation of an …
Papaya (Carica Papaya) Seed As A Low-Cost Sorbent For Zinc Removal, Siew-Teng Ong, Shiau-Ping Yip, Pei-Sin Keng, Siew-Ling Lee, Yung-Tse Hung
Papaya (Carica Papaya) Seed As A Low-Cost Sorbent For Zinc Removal, Siew-Teng Ong, Shiau-Ping Yip, Pei-Sin Keng, Siew-Ling Lee, Yung-Tse Hung
Civil and Environmental Engineering Faculty Publications
The potential of using papaya seed as a sorbent for the removal of Zn from aqueous solution was investigated. The sorption characteristics of the sorbent was studied under various experimental conditions, such as pH, contact time, concentration of Zn(II), agitation rate and sorbent’s particle size. The equilibrium data have been studied using Langmuir, Freundlich and Brunauer-Emmett-Teller equations. The best correlation was obtained using Langmuir isotherm with the regression coefficient value of 0.9799 and maximum sorption capacity of 19.88 mg/g. The effective pH for the maximum uptake of Zn(II) was at pH 5.0. An increase in percentage uptake of Zn(II) can …
Radial Consolidation Modelling Incorporating Downdrag Effect For A Multi-Layer Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna
Radial Consolidation Modelling Incorporating Downdrag Effect For A Multi-Layer Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna
Faculty of Engineering - Papers (Archive)
A system of vertical drains (PVDs) with preloading is a successful method for promoting horizontal drainage and accelerating soil consolidation. A piecewise technique is used to capture the radial consolidation in the multi-layer soil system to incorporate (a) the effect of soil downdrag and (b) smear zone where soil permeability varying linearly. The effect of soil dragged down from the upper soil layer into the lower layer has been analysed in terms of required time for consolidation. It can be seen that the consolidation of the multi layer soil depends on the interaction between 2 adjacent layer, penetration depth, and …
Track Stabilisation With Geosynthetics And Geodrains, And Performance Verification Through Field Monitoring And Numerical Modelling, Buddhima Indraratna, S Nimbalkar, Cholachat Rujikiatkamjorn
Track Stabilisation With Geosynthetics And Geodrains, And Performance Verification Through Field Monitoring And Numerical Modelling, Buddhima Indraratna, S Nimbalkar, Cholachat Rujikiatkamjorn
Faculty of Engineering - Papers (Archive)
All over the world, ballasted railway tracks form one of the major transportation networks designed to provide heavy haul freight and passenger traffic. However, large cyclic loading from heavy axle trains operating at high speeds often causes excessive deformation and degradation of ballast, as well as unacceptable differential settlement of compressible foundation and, or pumping of the soft subgrade soils. The problem becomes more severe under high impact loads due to rail or wheel imperfections, causing accelerated ballast breakage. A proper understanding of load transfer mechanisms and their effects on track deformations are essential prerequisites for minimising maintenance costs. The …
Modelling Of Temperature-Dependent Growth Kinetics Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Zhengyi Jiang, Dongbin Wei, Xiaodong Wang, Quan Yang
Modelling Of Temperature-Dependent Growth Kinetics Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Zhengyi Jiang, Dongbin Wei, Xiaodong Wang, Quan Yang
Faculty of Engineering - Papers (Archive)
A numerical simulation, developed to predict the temperature distribution and calculate the growth rale of the oxide scale formed on the microalloyed low carbon steel during the laminar cooling of hot strip rolling, was conducted by two-dimensional finite element method. The model takes into account the different thetmoPhYsical properties of the multilayered oxide scales and the film boundary conditions for the water jet impingement zone and the stable film boiling zone through the run-out table. Complied with the parabolic growth of the oxide layers and the distribution of the oxide phase, it is found that the present of wustite (FeO) …
Physical Modelling Of Soft Clay Consolidation Using Vacuum-Surcharge Method, Cholachat Rujikiatkamjorn
Physical Modelling Of Soft Clay Consolidation Using Vacuum-Surcharge Method, Cholachat Rujikiatkamjorn
Faculty of Engineering - Papers (Archive)
In Ihis paper, the large-scalc consolidation apparatus was employed to investi gate the performance of vacuum prelollding with conventional surcharge loading. Several tests were conducted \0 examine the efTect of a vacuum and associ(lled paTHlllclers Slich as smC:!T zone and soil permeability characteristics. The measured settlement and excess pore pressure indi cates that the vacuum application has certain benefits to control excess pore pressure for a given total loading applictlti on. The analyticn l modelling for rad ial consolidation and vacuum prcloading considering both variation of soil comprcssibility and perrneability was cmployed to predict the soil consolidation behaviour. It is …
Modélisation De La Mobilité Résidentielle En Vue D'Une Micro-Simulation Des Évolutions De Population, Eric Cornelis, Johan Barthelemy, Xavier Pauly, Fabien Walle
Modélisation De La Mobilité Résidentielle En Vue D'Une Micro-Simulation Des Évolutions De Population, Eric Cornelis, Johan Barthelemy, Xavier Pauly, Fabien Walle
Faculty of Engineering and Information Sciences - Papers: Part A
Quels sont les déterminants de la mobilité résidentielle en Belgique ? Quand on déménage, quels sont les facteurs de choix d'une nouvelle commune de résidence ? Telles étaient les questions au cœur du projet MOBLOC. Dans ce cadre, un modèle a été développé en deux parties: un modèle de propension à migrer et un modèle de choix de nouvelle localisation. L'objectif étant de travailler avec un niveau de désagrégation spatiale fin (les 589 communes belges), des outils de micro-simulation étaient également nécessaires. La méthode originale développée par le GRT pour créer des populations synthétiques est donc utile de même que …
The Sensitivity Of Particle Parameters In Discrete Element Modelling Of Belt Conveyor Transfers, David B. Hastie, Peter W. Wypych
The Sensitivity Of Particle Parameters In Discrete Element Modelling Of Belt Conveyor Transfers, David B. Hastie, Peter W. Wypych
Faculty of Engineering and Information Sciences - Papers: Part A
As discrete element modelling (DEM) becomes more widely used as a design tool, its suitability to modelling belt conveyor applications including conveyor transfers and conveyor trajectories is becoming more recognised. The accuracy of the data inputted for both the system geometry and particle perspective are vital if the outputs obtained from DEM simulations are to be considered valid. Bench-scale testing can readily obtain a range of particle parameters, however, there are others that can be more difficult to determine. This paper focuses on two such parameters; coefficient of rolling friction and shear modulus. A series of sensitivity analyses have been …
Modelling A Longwall Production System Using Flexsim 3d Simulation Software, D Cai, E Baafi, I Porter
Modelling A Longwall Production System Using Flexsim 3d Simulation Software, D Cai, E Baafi, I Porter
Faculty of Engineering and Information Sciences - Papers: Part A
Longwall mining accounts for more than 75% of underground coal production in Australia. It is a popular underground coal mining method worldwide, mainly due to its high extraction ratio, high productivity and increased safety due to improved powered support units. A longwall system requires significant capital investment, and it is necessary to minimise the financial risk associated with this investment. Minimisation of this financial risk requires a sound knowledge of the relationship between underlying operational/technical constraints and associated costs. A discrete simulation model using the Flexsim 3D virtual reality environment has been developed to assist management evaluate the impact of …
Towards Modelling Real Time Constraints, Amir Ashamalla, Ghassan Beydoun, Graham Low, Jun Yan
Towards Modelling Real Time Constraints, Amir Ashamalla, Ghassan Beydoun, Graham Low, Jun Yan
Faculty of Engineering and Information Sciences - Papers: Part A
Software agents are highly autonomous, situated and interactive software components. They autonomously sense their environment and respond accordingly. Agents behaviours are often constrained by by real time constraints such as the time in which the agent is expected to respond .i.e. time needed for a task to complete. Failing to meet such a constraint can result in a task being not achieved. This possibly causes an agent or a system to fail, depending on how critical the task is to the agent or system as a whole. Our research aims at identifying and modelling real time constraints in the early …
Cognitive Processes In Object-Oriented Requirements Engineering Practice: Analogical Reasoning And Mental Modelling, Linda Dawson
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 …
Probing And Modelling The Localized Self-Mixing In A Gan/Algan Field-Effect Terahertz Detector, J D. Sun, H Qin, R A. Lewis, Y F. Sun, X Y. Zhang, Y Cai, D M. Wu, B S. Zhang
Probing And Modelling The Localized Self-Mixing In A Gan/Algan Field-Effect Terahertz Detector, J D. Sun, H Qin, R A. Lewis, Y F. Sun, X Y. Zhang, Y Cai, D M. Wu, B S. Zhang
Faculty of Engineering - Papers (Archive)
In our previous work, we inferred the existence of localized self-mixing in an antenna-coupled field-effect terahertz detector. In this Letter, we report a quasistatic self-mixing model taking into account the localized terahertz fields and its verification by comparing the simulated results with the experimental data in a two-dimensional space of the gate voltage and the drain/source bias. The model well describes the detector characteristics: not only the magnitude, but also the polarity, of the photocurrent can be tuned. The existence of strongly localized self-mixing in such detectors is confirmed.
3d Numerical Modelling Of Hexagonal Wire Mesh Reinforced Embankment On Soft Bangkok Clay, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Dennes T. Bergado
3d Numerical Modelling Of Hexagonal Wire Mesh Reinforced Embankment On Soft Bangkok Clay, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Dennes T. Bergado
Faculty of Engineering - Papers (Archive)
The numerical modeling of the full scale test embankment reinforced with hexagonal wire mesh was analyzed using finite difference method under three dimensional (3D) conditions to reflect the actual embankment dimensions. In the analysis, the 3D finite difference simulation using 5 times of vertical laboratory permeability can reasonably predict its behavior on soft foundation. In comparison with the field measurements, the predicted results from 3D analysis reasonably agreed with measured data including vertical settlement, excess pore pressures and lateral displacements. Thus, the actual embankment geometry and the selected permeability influenced the behavior of the reinforced embankment constructed on soft ground …
Modeling Of Low Coherence Interferometry Using Broadband Multi-Gaussian Light Sources, Paul Jansz, Steven Richardson, Graham Wild, Steven Hinckley
Modeling Of Low Coherence Interferometry Using Broadband Multi-Gaussian Light Sources, Paul Jansz, Steven Richardson, Graham Wild, Steven Hinckley
Research outputs 2012
Using a low coherence interferometry (LCI) model, a comparison of broadband single-Gaussian and multi-Gaussian light sources has been undertaken. For single-Gaussian sources, the axial resolution improves with the source bandwidth, confirming the coherence length relation that the resolution for single Gaussian sources improves with increasing spectral bandwidth. However, narrow bandwidth light sources result in interferograms with overlapping strata peaks and the loss of individual strata information. For multiple-Gaussian sources with the same bandwidth, spectral side lobes increase, reducing A-scan reliability to show accurate layer information without eliminating the side lobes. The simulations show the conditions needed for the resolution of …
Optimisation Of Power Detection Interrogation Methods For Fibre Bragg Grating Sensors, Graham Wild, Steven Richardson
Optimisation Of Power Detection Interrogation Methods For Fibre Bragg Grating Sensors, Graham Wild, Steven Richardson
Research outputs 2012
We present a method to optimise the performance of power detection interrogation systems for fibre Bragg grating sensors. The performance of the different systems can be optimised in terms of their sensitivity and/or dynamic range.
Low Coherence Interferometry Modelling Using Combined Broadband Gaussian Light Sources, Paul Jansz, Graham Wild, Steven Richardson, Steven Hinckley
Low Coherence Interferometry Modelling Using Combined Broadband Gaussian Light Sources, Paul Jansz, Graham Wild, Steven Richardson, Steven Hinckley
Research outputs 2012
Using a Low Coherence Interferometry (LCI) model, a comparison of broadband single-Gaussian and multi-Gaussian light sources has been undertaken. For single-Gaussian sources, the axial resolution improved with source bandwidth, confirming the coherence length relation that resolution for single Gaussian sources improves with increasing spectral bandwidth. However, narrow bandwidth light sources resulted in interferograms with overlapping strata peaks and the loss of individual strata information. For multiple-Gaussian sources with the same bandwidth, spectral side lobes increased, reducing A-scan reliability to show accurate layer information without eliminating the side lobes. The simulations show the conditions needed for resolution of strata information for …