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Full-Text Articles in Physical Sciences and Mathematics
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 …
Atollgame: A Companion Modelling Experience In The Pacific, A Dray, Pascal Perez, Christophe Le Page, Patrick D'Aquino, Ian White
Atollgame: A Companion Modelling Experience In The Pacific, A Dray, Pascal Perez, Christophe Le Page, Patrick D'Aquino, Ian White
SMART Infrastructure Facility - Papers
Multi-Agent Systems (MAS) have been developed to study the interaction between societies and the environment. Here we use MAS in conjunction with a Companion Modelling (ComMod) approach to develop a Negotiation Support System for groundwater management in Tarawa, Republic of Kiribati. In agreement with the complex and dynamic nature of the processes under study, the ComMod approach requires a permanent and iterative confrontation between theories and field circumstances. Therefore, it is based on repetitive back and forth steps between the model and the field situation. The methodology applied in Tarawa relies on 3 successive stages. First, a Global Targeted Appraisal …
Towards An Art And Science Of Decision Aiding For Water Management And Planning: A Participatory Modelling Process, Katherine A. Daniell, Ian White, Nils Ferrand, Alexis Tsoukias, Stewart Burn, Pascal Perez
Towards An Art And Science Of Decision Aiding For Water Management And Planning: A Participatory Modelling Process, Katherine A. Daniell, Ian White, Nils Ferrand, Alexis Tsoukias, Stewart Burn, Pascal Perez
SMART Infrastructure Facility - Papers
Planning and management of water resources are faced with increasingly high levels of complexity, uncertainty and conflict. Traditional technical and top-down management strategies have proved inadequate, forcing a move to more "integrated" forms of management, planning and decision making that can include stakeholders and communities, as well as technical experts and policy makers. These integrated forms of management require not only good technical or scientific ability, but a range of "art-like" skills including communication, creativity and the capacity to acknowledge and integrate diverse points of view. However, processes designed to aid such inter-organisational or multi-stakeholder decisionmaking are rare and in …
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.