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Full-Text Articles in Physical Sciences and Mathematics
Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana
Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana
Faculty of Informatics - Papers (Archive)
The discovery of carbon nanostructures, such as graphene and carbon nanotubes, has led to the creation of many novel nano-devices. In this paper, we consider an environmental application of carbon nanostructures for filtering and adsorbing polycyclic aromatic hydrocarbons (PAHs) which are environmental pollutants. We mathematically investigate the adsorption of PAHs onto a graphene sheet and determine the underlying mechanisms of suction of PAHs into a carbon nanotube. We adopt a continuum approach together with the semi-empirical Lennard-Jones potential to determine van der Waals interaction forces and energies. Results obtained here for certain PAHs are well in agreement with existing experimental …
Modelling Pattern Formation In Plants, M P. Edwards, S Pereverzyev, R S. Anderssen
Modelling Pattern Formation In Plants, M P. Edwards, S Pereverzyev, R S. Anderssen
Faculty of Informatics - Papers (Archive)
Performing simulations with simple models is a key activity in the recovery of information about the mechanisms which underlie the observed dynamics of biological processes, such as the posi- tioning of the hairs (trichomes) on the leaves of plants. The discovery of a robust representative model is a highly non-trivial process. Without appropriate constraints to regularize the choice of a model, the non-uniqueness of possibilities is vast. As acknowledged by Young (1983) in his modelling of pea leaf development, the degree of non-uniqueness can be reduced by constraining the model to reproduce the patterns observed in mutants as well as …
Supporting Developers In Complex Systems Modelling, Antonio A. Lopez-Lorca, Ghassan Beydoun, Rodrigo Martinez-Bejar, Holly Tootell
Supporting Developers In Complex Systems Modelling, Antonio A. Lopez-Lorca, Ghassan Beydoun, Rodrigo Martinez-Bejar, Holly Tootell
Faculty of Informatics - Papers (Archive)
Development of complex systems often requires building a large number of models with many interconnections and dependencies among them. The success of a project can be compromised by cognitive overload or limits of developers, who might miss relationships between elements of the models. Developing Multi-Agent Systems (MAS) is a typical example of where this may occur. Despite of its potential, this technology has not yet been widely adopted by industry due to its complexity and frequent errors in modelling activities. These errors typically propagate to later phases of the MAS development lifecycle, becoming costlier to fix and then lowering the …
Modelling The Effects Of Moisture Content In Compost Piles, T Luangwilai, H S. Sidhu, M I. Nelson, Xiao Dong Chen
Modelling The Effects Of Moisture Content In Compost Piles, T Luangwilai, H S. Sidhu, M I. Nelson, Xiao Dong Chen
Faculty of Informatics - Papers (Archive)
This paper considers the self-heating process occurring in a compost pile using one- and two-dimensional spatially-dependent models and incorporating terms that account for self-heating due to both biological and oxidative mechanisms. Biological heat generation is known to be present in most industrial processes handling large volumes of bulk organic materials. The heat release rate due to biological activity is modelled by a function which is, at sufficiently low temperatures, a monotonically increasing function of temperature and, at higher temperatures, a monotonically decreasing function of temperature. This functionality represents the fact that microorganisms die or become dormant at high temperatures. The …
Modelling Interaction Of Atoms And Ions With Graphene, James M. Hill, Yue Chan
Modelling Interaction Of Atoms And Ions With Graphene, James M. Hill, Yue Chan
Faculty of Informatics - Papers (Archive)
In this Letter, the authors inve´stigate the interaction of various atoms/ions with a graphene sheet and two parallel graphene sheets using the continuous approximation and the 6–12 Lennard-Jones potential. The authors assume that the carbon atoms are smeared across the surface of the graphene sheet so that the total interaction between the single atom/ion and the graphene sheet can be approximated by a surface integration over the graphene sheet. They determine the equilibrium position for the atom/ion on the surface of the graphene sheet and the minimum intermolecular spacing between two graphene sheets. This minimum spacing is by symmetry twice …
Dynamic Modelling, Validating And Fine-Tuning Of Engineering Curriculum, Fazel Naghdy
Dynamic Modelling, Validating And Fine-Tuning Of Engineering Curriculum, Fazel Naghdy
Faculty of Informatics - Papers (Archive)
The undergraduate Engineering schools in Australia are required to embed and assess the Competency Standards defined by the Engineers Australia in their curriculum. At the same time, embedding graduate attributes in the curriculum has become an important element in the quality assurance processes of universities. The embedding and mapping are only the first step in a long term process. The mapping should be validated empirically and reviewed in a repeating cycle towards an effective and optimal curriculum. This will require a rigorous action learning process for creating and cyclic validation of a living curriculum. The conceptual development and early stages …
Application Of Microsimulation To The Modelling Of Epidemics And Terrorist Attacks, Ian Piper, Daniel Keep, Tony Green, Ivy Zhang
Application Of Microsimulation To The Modelling Of Epidemics And Terrorist Attacks, Ian Piper, Daniel Keep, Tony Green, Ivy Zhang
Faculty of Informatics - Papers (Archive)
In this paper, a novel approach to behavioural modelling is presented with reference to biological infection spread in communities. Its potential application to various terrorist-related scenarios is discussed in relation to attack point simulation and interdiction simulation.
Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky
Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky
Faculty of Informatics - Papers (Archive)
This paper presents the linearised small-signal dynamic modelling of hydroelectric turbine-generator (TG) unit with CIGRE first high-voltage direct current (HVDC) benchmark system in the synchronously rotating D-Q reference frame for small-signal stability analysis. The interaction behaviour between the hydroelectric unit and the dynamics and control of HVDC system is investigated utilising eigen-analysis,participation factor analysis and by conducting sensitivity studies. The computation of eigenvalues and eigenvectors for small signal stability analysis provides an invaluable insight onto the power system dynamic behaviour by characterising the damping and frequency of the system oscillatory modes. Theconsequences of different operating conditions, such as active and …
Modelling Hydrogen Adsorption Within Spherical, Cylindrical And Slit-Shaped Cavities, Aaron Thornton, James M. Hill
Modelling Hydrogen Adsorption Within Spherical, Cylindrical And Slit-Shaped Cavities, Aaron Thornton, James M. Hill
Faculty of Informatics - Papers (Archive)
The ability to store hydrogen in a highly dense state within absorbents via the mechanism of adsorption has become a critical step in order to make a hydrogen powered automobile a practical reality. Absorbents are composed of nano-scale cavities (or pores) designed in such a way that hydrogen will adsorb onto the internal surface and thus be stored densely and safely enough for transport at ambient conditions. This work investigates the effect of the geometry of the cavity shape by applying a new mathematical model for predicting gas uptake, which is based on calculating the van der Waals' interactions for …
Simulations In 3d Tactics, Interdiction And Multi-Agent Modelling, A. R. Green, I. C. Piper, Daniel Keep, C. J. Flaherty
Simulations In 3d Tactics, Interdiction And Multi-Agent Modelling, A. R. Green, I. C. Piper, Daniel Keep, C. J. Flaherty
Faculty of Informatics - Papers (Archive)
The analysis of vulnerabilities in large complex spaces is fundamentally problematic. The lack of capacity to generate a threat assessment merely exacerbates this problem. Lacking as well, in current literature is a developed methodology. To overcome this problem, we propose an approach using multi-agent modelling, which is also melded with three dimensional (3D) tactical understandings. Our approach builds on a microsimulation decision support tool, which was developed for a behavioural simulation of CBRN events. Microsimulation is based on the individual; who as an individual has a number of attributes, and which are stochastic (when repeated within an attribute). This approach …
Modelling Of Hydraulic Governor-Turbine For Control Stabilisation, Michael Negnevitsky, Kashem Muttaqi, Yin Chin Choo
Modelling Of Hydraulic Governor-Turbine For Control Stabilisation, Michael Negnevitsky, Kashem Muttaqi, Yin Chin Choo
Faculty of Informatics - Papers (Archive)
Power system performance is affected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line or a rapid change of load. Accurate modelling of hydraulic governor-turbines is essential to characterise and diagnose the system response during an emergency. In this article, both detailed and simplified hydraulic systems governed by proportional-integral-derivative and proportional-integral controllers are modelled. This article examines their transient responses to disturbances through simulation in Matlab/Simulink. The article also investigates the dynamic performance of an isolated hydraulic system through evaluating stability margins, eigenvalues, root loci and frequency …
Application Of Fuzzy Narx To Human Gait Modelling And Identification, Seyed Hesami, Fazel Naghdy, David A. Stirling, Harold C. Hill
Application Of Fuzzy Narx To Human Gait Modelling And Identification, Seyed Hesami, Fazel Naghdy, David A. Stirling, Harold C. Hill
Faculty of Informatics - Papers (Archive)
A new modelling and classification approach for human gait is proposed. Body movements are obtained using a sensor suit recording inertial signals that are subsequently modelled on a humanoid frame with 23 degrees of freedom (DOF). Measured signals include position, velocity, acceleration, orientation, angular velocity and angular acceleration. The identification and modelling method segments the stream of non–linear movement data on the basis of the features extracted from the sensor signals. A model is then created for the movement of every individual. This model is used as a dynamic finger print for that specific individual. In the future stages of …
3d Geometric Modelling Of Hand-Woven Textile, Hooman Shidanshidi, Fazel Naghdy, Golshah Naghdy, Diana Wood Conroy
3d Geometric Modelling Of Hand-Woven Textile, Hooman Shidanshidi, Fazel Naghdy, Golshah Naghdy, Diana Wood Conroy
Faculty of Informatics - Papers (Archive)
Geometric modeling and haptic rendering of textile has attracted significant interest over the last decade. A haptic representation is created by adding the physical properties of an object to its geometric configuration. While research has been conducted into geometric modeling of fabric, current systems require time-consuming manual recognition of textile specifications and data entry. The development of a generic approach for construction of the 3D geometric model of a woven textile is pursued in this work. The geometric model would be superimposed by a haptic model in the future work. The focus at this stage is on hand-woven textile artifacts …
Empirical Modelling Of Human Gaits For Bipedal Robots, Matthew Field, David A. Stirling, Fazel Naghdy, Zengxi Pan
Empirical Modelling Of Human Gaits For Bipedal Robots, Matthew Field, David A. Stirling, Fazel Naghdy, Zengxi Pan
Faculty of Informatics - Papers (Archive)
Modelling of human motion through a discrete sequence of motion primitives, retaining elements of skillful or unique motion of an individual is addressed. Using wireless inertial motion sensors, a skeletal model of the fluid human gait was gathered. The posture of the human model is described by nine sets of euler angles for each sample. An intrinsic classification algorithm known as Minimum Message Length encoding (MML) is deployed to segment the stream of data and subsequently formulate certain Gaussian Mixture Models (GMM) that contain a plausible range of motion primitives. The removal of certain less seemingly important modes has been …
Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana
Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana
Faculty of Informatics - Papers (Archive)
Continmuum based models are presented here for certain boron nitride and carbon nanostructures.
Modelling Mas-Specific Security Features, Ghassan Beydoun, Graham C. Low, Haralambos Mouratidis, Brian Henderson-Sellers
Modelling Mas-Specific Security Features, Ghassan Beydoun, Graham C. Low, Haralambos Mouratidis, Brian Henderson-Sellers
Faculty of Informatics - Papers (Archive)
In this paper, we pursue a modelling approach to address security requirements for multi-agent systems (MAS). This will allow developers to account for both the system and agent-specific security requirements of a MAS during the requirements phase and throughout the whole Software Development Lifecycle of the system. We focus on autonomy, mobility and cooperation of individual agents and how these create additional security vulnerabilities to the system. In proposing a set of generic modelling primitives for these engendered requirements in the analysis of the MAS, we extend our recently proposed MAS metamodel.
Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry J. Cox, Ngamta Thamwattana, James M. Hill
Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry J. Cox, Ngamta Thamwattana, James M. Hill
Faculty of Informatics - Papers (Archive)
The discovery of fullerenes C60 and carbon nanotubes has created an enormous impact on nanotechnology. Because of their unique mechanical and electronic properties, such as low weight, high strength, flexibility and thermal stability, fullerenes C60 and carbon nanotubes are of considerable interest to researchers from many scientific areas. One problem that has attracted much attention is the creation of gigahertz oscillators. While there are difficulties for micromechanical oscillators, or resonators, to reach a frequency in the gigahertz range, it is possible for nanomechanical systems to achieve this. A number of studies have found that the sliding of the …
Modelling The Induced Force Of Attraction In Electrorheological Nanofluids, Barry J. Cox, Ngamta Thamwattana, James M. Hill
Modelling The Induced Force Of Attraction In Electrorheological Nanofluids, Barry J. Cox, Ngamta Thamwattana, James M. Hill
Faculty of Informatics - Papers (Archive)
The problem of electric-field induced force between spheres is fundamental to electrorheological fluids. In this paper we summarize recent work, and in particular present an exact solution to the electrostatic problem of dielectric spheres subject to an externally applied electric field. The numerical results are compared to published experimental data and the solution is shown to accurately predict the low-frequency experimental results at all measured interstices and particularly is applicable to nanosized spheres in close proximity. This method is applicable to nonidentical spheres and results indicate a genuine maximum in the attractive force between spheres exists, which depends on relative …
Mathematical Modelling In Nanotechnology, Ngamta Thamwattana, James M. Hill
Mathematical Modelling In Nanotechnology, Ngamta Thamwattana, James M. Hill
Faculty of Informatics - Papers (Archive)
The interaction of nano particles with conventional materials dramatically changes all the physical parameters, which usually characterize the bulk material. The nano particles constitute highly reactive isolated sites to the extent that it leads to a change in the electronic structure of the nano composite, and accordingly all the physical properties, such as thermal, mechanical and electrical properties become different from those of the bulk material. To successfully exploit nano composites as components and devices, this fundamental shift of physical properties must be properly understood and accurately modelled. While experimentation is crucial, a theoretical understanding is also necessary and with …
Modelling Of High Temperature Superconducting Wires And Coils, Christopher David Cook, T Hardono
Modelling Of High Temperature Superconducting Wires And Coils, Christopher David Cook, T Hardono
Faculty of Informatics - Papers (Archive)
This paper discusses modelling techniques for high temperature superconducting (HTSC) wires and coils. Models are developed based on the behaviour of Bi-2223/Ag wires and coils. For many power-engineering applications it is necessary to form HTSC wires into coils. PSpice models for HTSC coils will be presented in this paper. The aim is to develop models for HTSC wires and coils so that they can be treated as circuit elements in PSpice. The critical current of a coil will in general be different from the wire it is manufactured from and this change in current for a HTSC coil will be …
Modelling Of Color Cross-Talk In Cmos Image Sensors, Wanqing Li, Philip Ogunbona, Yan Shi, Igor Kharitonenko
Modelling Of Color Cross-Talk In Cmos Image Sensors, Wanqing Li, Philip Ogunbona, Yan Shi, Igor Kharitonenko
Faculty of Informatics - Papers (Archive)
This paper presents a way to model the cross-talk effect in CMOS image sensors. Two algorithms are derived from the model; both of them work on the Bayer raw data and have low computational complexity. Experiments on Macbeth color chart and real images have shown the effectiveness of the modeling to eliminate the cross-talk effect and produce better quality images with traditional color interpolation and correction algorithms designed for CCD image sensors.
Using Boosting To Simplify Classification Models, V. Wheway
Using Boosting To Simplify Classification Models, V. Wheway
Faculty of Informatics - Papers (Archive)
Ensemble classification techniques such as bagging, boosting and arcing algorithms have been shown to lead to reduced classification errors on unseen cases and seem immune to the problem of overfitting. Several explanations for the reduction in generalisation error have been presented, with recent authors defining and applying diagnostics such as "edge" and "margin". These measures provide insight into the behaviour of ensemble classifiers, but can they be exploited further? In this paper, a four-stage classification procedure in introduced, which is based on an extension of edge and margin analysis. This new procedure allows inverse sub-contexts and difficult border regions to …
Behavioural Modelling Of High Temperature Superconducting Wires And Coils For Power Engineering Applications, Thomas Hardjono, Christopher David Cook, Sarath Perera
Behavioural Modelling Of High Temperature Superconducting Wires And Coils For Power Engineering Applications, Thomas Hardjono, Christopher David Cook, Sarath Perera
Faculty of Informatics - Papers (Archive)
Many aspects of the behaviour of high temperature superconducting (HTS) wires are well understood for dc applications. However, models of HTS suitable for use in circuit analysis by power engineers designing HTS applications are not readily available. This paper describes the initial development of suitable models for HTS wire. The V-I characteristics for wires carrying dc transport current can be empirically determined using a power law V=kIn. Experimentally measured V-I characteristics are fitted using the above power law. This enables the simulation of the behaviour of Bi-2223/Ag wire using the well-known circuit simulator PSpice. Other factors affecting the dc critical …
Application Of Visual Modelling In Image Restoration And Colour Image Processing, Aziz Qureshi, Philip Ogunbona
Application Of Visual Modelling In Image Restoration And Colour Image Processing, Aziz Qureshi, Philip Ogunbona
Faculty of Informatics - Papers (Archive)
This paper describes the application of human visual models in (i) defining a visually uniform colour representation space and (ii) the formulation of visually weighted Kalman filtering for image restoration. The former being useful in colour image quantisation and compression. For (i), the uniformity of chromaticity differences at the ouptut of Frei ’s colour vision model [3] is tested and compensated for by using MacAdam’s uniform chromaticity space. For (ii), the dynamical image model of the Kalman filter is visually weighted using the frequency response of Stockham’s model [l] of human vision.