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2012

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Full-Text Articles in Physical Sciences and Mathematics

A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark I. Nelson, Annette L. Worthy Dec 2012

A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark I. Nelson, Annette L. Worthy

Associate Professor Annette Worthy

Many industrial processes, particularly in the food industry, produce slurries or wastewaters containing high concentrations of biodegradable organic materials. Before these contaminated wastewaters can be discharged the concentration of the biodegradable organic pollutant must be reduced. One way to do this is to pass the wastewater through a bioreactor containing biomass which grows through consumption of the pollutant. Anaerobic conditions are often favoured for the processing of waste materials with high levels of biodegradable organic pollutants as these can be removed with low investment and operational costs. We investigate the steady state effluent concentration leaving a cascade of two reactors. …


Towards Knowledge Management In Sports Event Management: Context Analysis Of Malaysian Biannual Games With Commonkads, Azizul Rahman Abdul Ghaffar, Ghassan Beydoun, Jun Shen, William Tibben Dec 2012

Towards Knowledge Management In Sports Event Management: Context Analysis Of Malaysian Biannual Games With Commonkads, Azizul Rahman Abdul Ghaffar, Ghassan Beydoun, Jun Shen, William Tibben

Dr William Tibben

Context Analysis (CA) is typically used as an early phase preceding the development of a knowledge-based systems in order to indicate how the system should interact with its environment and the various stakeholders. We undertake a detailed context analysis of business processes of the Malaysian Games (MG)to highlight blind spots of the process and enable the identification of an initial sports event knowledge management (KM) framework. Firstly, our CommonKADS driven analysis highlights how we can improve the business process and enable the organization to develop, distribute and apply its knowledge resources effectively. Secondly, the paper highlights specific features about the …


Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling Dec 2012

Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling

Dr David Stirling

During the past two decades, there has been a considerable number of Power Quality (PQ) monitoring programs completed throughout the world. The information collected during these surveys can provide a detailed picture of the expected electrical environment help utilities to plan their future networks in relation to power quality performance. The mass of data gathered for a sample of sites of a large-scale power quality (PQ) survey of this nature has the potential to reveal good and bad influences on power quality if an appropriate procedure for analysis can be determined. If it is known which characteristics are more important …


Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson Dec 2012

Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson

Dr David Stirling

The rapid increase in the size of databases required to store power quality monitoring data has demanded new techniques for analysing and understanding the data. One suggested technique to assist in analysis is data mining. Data mining is a process that uses a variety of data analysis tools to identify hidden patterns and relationships within large samples of data. This paper presents several data mining tools and techniques that are applicable to power quality data analysis to enable efficient reporting of disturbance indices and identify network problems through pattern recognition. This paper also presents results of data mining techniques applied …


Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson Dec 2012

Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson

Dr Duane Robinson

The rapid increase in the size of databases required to store power quality monitoring data has demanded new techniques for analysing and understanding the data. One suggested technique to assist in analysis is data mining. Data mining is a process that uses a variety of data analysis tools to identify hidden patterns and relationships within large samples of data. This paper presents several data mining tools and techniques that are applicable to power quality data analysis to enable efficient reporting of disturbance indices and identify network problems through pattern recognition. This paper also presents results of data mining techniques applied …


Kinetic Analysis Of Oleic Acid Esterification Using Lipolytic Enzyme As Catalyst, Mohd S. Mahmud, James W. Ryan, Cyrus Cooper, Tomasz Safinski, Mark I. Nelson, Harvinder S. Sidhu, Soji A. Adesina Dec 2012

Kinetic Analysis Of Oleic Acid Esterification Using Lipolytic Enzyme As Catalyst, Mohd S. Mahmud, James W. Ryan, Cyrus Cooper, Tomasz Safinski, Mark I. Nelson, Harvinder S. Sidhu, Soji A. Adesina

Associate Professor Mark Nelson

This paper deals with the esterification kinetics of oleic acid (OA) using ethanol (EtOH) over acrylic-supported lipase from Aspergillus niger (Novozym 435) as catalyst. The reaction was carried out in a stirred 500 mL Pyrex glass reactor at 45oC under conditions with negligible external and internal transport resistances. Reaction runs in a microaqueous medium employed OA: EtOH ratio, b, between 0.01 to 2.0 without initial addition of water. The rate dependency on reactant concentration has a maximum at b=0.9, just below the stoichiometric ratio, and was therefore described by a Michaelis- Menten kinetic expression implicating irreversible surface reaction between adsorbed …


Autoignition Of Hydrocarbons In A Batch Reactor: Analysis Of A Reduced Model, Mark I. Nelson, E Balakrishnan Dec 2012

Autoignition Of Hydrocarbons In A Batch Reactor: Analysis Of A Reduced Model, Mark I. Nelson, E Balakrishnan

Associate Professor Mark Nelson

n the late 1960s Gray and Yang developed the first reduced kinetic model for the oxidation of hydrocarbon fuels that qualitatively described many features observed experimentally. Since then a number of reduced kinetic models have been proposed in the literature. In this contribution we analyse the steady-state behaviour of one such scheme. The chemical component of the model contains four chemical species undergoing six reactions. By making a pool-chemical approximation this system is reduced to three coupled non-linear differential equations: a temperature equation and equations for two reactive chemical intermediates. It is shown that any steady-state solution of this model …


A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Non-Competitive Product Inhibition. Iii. Linear Inhibition, Mark I. Nelson, Wei X. Lim Dec 2012

A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Non-Competitive Product Inhibition. Iii. Linear Inhibition, Mark I. Nelson, Wei X. Lim

Associate Professor Mark Nelson

The steady-state production of a product produced through the growth of microorganisms in a continuous flow bioreactor is presented. A generalised reactor model is used in which both the classic well-stirred bioreactor and the idealised membrane bioreactor are considered as special cases. The reaction is assumed to be governed by Monod growth kinetics subject to non-competitive product inhibition. Inhibition is modelled as a decreasing linear function of the product concentration with a finite cut-off. This reaction scheme is well documented in the literature, although a stability analysis of the governing equations has not previously been presented. The steady-state solutions for …


Towards Knowledge Management In Sports Event Management: Context Analysis Of Malaysian Biannual Games With Commonkads, Azizul Rahman Abdul Ghaffar, Ghassan Beydoun, Jun Shen, William Tibben Dec 2012

Towards Knowledge Management In Sports Event Management: Context Analysis Of Malaysian Biannual Games With Commonkads, Azizul Rahman Abdul Ghaffar, Ghassan Beydoun, Jun Shen, William Tibben

Associate Professor Ghassan Beydoun

Context Analysis (CA) is typically used as an early phase preceding the development of a knowledge-based systems in order to indicate how the system should interact with its environment and the various stakeholders. We undertake a detailed context analysis of business processes of the Malaysian Games (MG)to highlight blind spots of the process and enable the identification of an initial sports event knowledge management (KM) framework. Firstly, our CommonKADS driven analysis highlights how we can improve the business process and enable the organization to develop, distribute and apply its knowledge resources effectively. Secondly, the paper highlights specific features about the …


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 Dec 2012

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

Dr Ashish Agalgaonkar

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 …


The Fourier Spectrum Analysis Of Optical Feedback Self-Mixing Signal Under Weak And Moderate Feedback, Xiaojun Zhang, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo Dec 2012

The Fourier Spectrum Analysis Of Optical Feedback Self-Mixing Signal Under Weak And Moderate Feedback, Xiaojun Zhang, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo

Dr Yanguang Yu

The spectrum characteristics of self-mixing signals observed in optical feedback self-mixing interferometry (OFSMI) is studied in this paper. The purpose is to provide guidance for the design of pre-processing techniques for eliminating noise or disturbance. The influence of two important parameters of the OFSMI system on the spectrum, that is, the optical feedback factor and the linewidth enhancment factor, are measured by means of Discrete Fourier transform (DFT). The simulated results show that, at a weak feedback, the OFSMI signals are strictly band limited in nature, with the cut-off frequencies being the vibration frequency and the fringe frequency respectively. Also …


Online Grocery Systems Design Through Task Analysis, Mark Freeman, Alison Freeman Dec 2012

Online Grocery Systems Design Through Task Analysis, Mark Freeman, Alison Freeman

Dr Mark Freeman

Purpose – Modelling users’ interactions online is envisaged to allow developers to increase the usability of online systems and will aid system developers in building better systems to meet users’ needs, hereby creating better system design processes. Design/methodology/approach – The normative task model that was developed in this paper was created through an expert review of 14 online grocery stores, using a reverse engineering technique to model the features of the stores’ ordering process. Findings – The research identified three main areas of user experience when undertaking the process of adding a product to an online trolley: attempting to retrieve …


Molecular Dynamics Analysis Of Apolipoprotein-D - Lipid Hydroperoxide Interactions: Mechanism For Selective Oxidation Of Met-93, Aaron J. Oakley, Surabhi Bhatia, Heath Ecroyd, Brett Garner Dec 2012

Molecular Dynamics Analysis Of Apolipoprotein-D - Lipid Hydroperoxide Interactions: Mechanism For Selective Oxidation Of Met-93, Aaron J. Oakley, Surabhi Bhatia, Heath Ecroyd, Brett Garner

Heath Ecroyd

Background: Recent studies suggest reduction of radical-propagating fatty acid hydroperoxides to inert hydroxides by interaction with apolipoprotein-D (apoD) Met93 may represent an antioxidant function for apoD. The nature and structural consequences of this selective interaction are unknown. Methodology/Principal Findings: Herein we used molecular dynamics (MD) analysis to address these issues. Longtimescale simulations of apoD suggest lipid molecules are bound flexibly, with the molecules free to explore multiple conformations in a binding site at the entrance to the classical lipocalin ligand-binding pocket. Models of 5s- 12s- and 15s hydroperoxyeicosatetraenoic acids were created and the lipids found to wrap around Met93 thus …


Fault Analysis Of The Katan Family Of Block Ciphers, Shekh Faisal Abdul-Latip, Mohammad Reza Reyhanitabar, Willy Susilo, Jennifer Seberry Dec 2012

Fault Analysis Of The Katan Family Of Block Ciphers, Shekh Faisal Abdul-Latip, Mohammad Reza Reyhanitabar, Willy Susilo, Jennifer Seberry

Professor Willy Susilo

In this paper, we investigate security of the KATAN family of block ciphers against differential fault attacks. KATAN consists of three variants with 32, 48 and 64-bit block sizes, called KATAN32, KATAN48 and KATAN64, respectively. All three variants have the same key length of 80 bits. We assume a single-bit fault injection model where the adversary is supposed to be able to corrupt a single random bit of the internal state of the cipher and this fault induction process can be repeated (by resetting the cipher); i.e., the faults are transient rather than permanent. First, we show how to identify …


Security Analysis Of Michael: The Ieee 802.11i Message Integrity Code, Jianyong Huang, Jennifer Seberry, Willy Susilo, Martin W. Bunder Dec 2012

Security Analysis Of Michael: The Ieee 802.11i Message Integrity Code, Jianyong Huang, Jennifer Seberry, Willy Susilo, Martin W. Bunder

Professor Willy Susilo

The latest IEEE 802.11i uses a keyed hash function, called Michael, as the message integrity code. This paper describes some properties and weaknesses of Michael. We provide a necessary and sufficient condition for finding collisions of Michael. Our observation reveals that the collision status of Michael only depends on the second last block message and the output of the block function in the third last round. We show that Michael is not collision-free by providing a method to find collisions of this keyed hash function. Moreover, we develop a method to find fixed points of Michael. If the output of …


Fault Analysis Of The Katan Family Of Block Ciphers, Shekh Faisal Abdul-Latip, Mohammad Reza Reyhanitabar, Willy Susilo, Jennifer Seberry Dec 2012

Fault Analysis Of The Katan Family Of Block Ciphers, Shekh Faisal Abdul-Latip, Mohammad Reza Reyhanitabar, Willy Susilo, Jennifer Seberry

Dr Reza Reyhanitabar

In this paper, we investigate security of the KATAN family of block ciphers against differential fault attacks. KATAN consists of three variants with 32, 48 and 64-bit block sizes, called KATAN32, KATAN48 and KATAN64, respectively. All three variants have the same key length of 80 bits. We assume a single-bit fault injection model where the adversary is supposed to be able to corrupt a single random bit of the internal state of the cipher and this fault induction process can be repeated (by resetting the cipher); i.e., the faults are transient rather than permanent. First, we show how to identify …


Charge Transport Properties Of Bo-Chelated Azadipyrromethenes, Tingrui Ma, Muyuan Zhao, Geneviève Sauvé Dec 2012

Charge Transport Properties Of Bo-Chelated Azadipyrromethenes, Tingrui Ma, Muyuan Zhao, Geneviève Sauvé

Intersections Fall 2020

Intramolecular BO-chelated azadipyrromethenes are promising organic semiconductors. Here, we evaluated the electron and hole mobility of a series of BO-chelated azadipyrromethenes using the Space Charge Limited Current(SCLC) method. In order to determine the mobility of the material, Mott Gurney's law was applied using the film thickness and slope of the J1/2 versus voltage plot in the SCLC graph. The best electron mobility observed for BO-chelated materials is 4.64—10-6 cm2V-1s-1 and the best hole mobility is 7.38—10-4 cm2V-1s-1. These results suggest that BO-chelated materials are promising p-type semiconductors for electronic applications.


Evaluating Participatory Modeling: Developing A Framework For Cross-Case Analysis. Socio-Economics And The Environment In Discussion (Seed), Natalie A. Jones, Pascal Perez, Thomas G. Measham, Gail J. Kelly, Patrick D'Aquino, Katherine Daniell, Anne Dray, Nils Ferrand Nov 2012

Evaluating Participatory Modeling: Developing A Framework For Cross-Case Analysis. Socio-Economics And The Environment In Discussion (Seed), Natalie A. Jones, Pascal Perez, Thomas G. Measham, Gail J. Kelly, Patrick D'Aquino, Katherine Daniell, Anne Dray, Nils Ferrand

Professor Pascal Perez

Participatory modeling is increasingly recognised as an effective way to assist collective decision-making processes in the domain of natural resource management. This paper introduces a framework for evaluating projects that have adopted a participatory modeling approach. This framework – known as the ‘Protocol of Canberra’ – was developed through a collaboration between French and Australian researchers engaged in participatory modeling and evaluation research. The framework seeks to assess the extent to which different participatory modeling practices reinforce or divert from the theoretical assumptions they are built upon. The paper discusses the application of the framework in three case-studies, two from …


Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling Nov 2012

Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling

Associate Professor Sarath Perera

During the past two decades, there has been a considerable number of Power Quality (PQ) monitoring programs completed throughout the world. The information collected during these surveys can provide a detailed picture of the expected electrical environment help utilities to plan their future networks in relation to power quality performance. The mass of data gathered for a sample of sites of a large-scale power quality (PQ) survey of this nature has the potential to reveal good and bad influences on power quality if an appropriate procedure for analysis can be determined. If it is known which characteristics are more important …


Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson Nov 2012

Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson

Associate Professor Sarath Perera

The rapid increase in the size of databases required to store power quality monitoring data has demanded new techniques for analysing and understanding the data. One suggested technique to assist in analysis is data mining. Data mining is a process that uses a variety of data analysis tools to identify hidden patterns and relationships within large samples of data. This paper presents several data mining tools and techniques that are applicable to power quality data analysis to enable efficient reporting of disturbance indices and identify network problems through pattern recognition. This paper also presents results of data mining techniques applied …


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 Nov 2012

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

Associate Professor Sarath Perera

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 …


Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona Nov 2012

Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona

Associate Professor Golshah Naghdy

Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for …


Further Analysis Of A Practical Hierarchical Identity-Based Encryption Scheme, Ying Sun, Yong Yu, Yi Mu Nov 2012

Further Analysis Of A Practical Hierarchical Identity-Based Encryption Scheme, Ying Sun, Yong Yu, Yi Mu

Professor Yi Mu

No abstract provided.


Hierarchical Model Building, Fitting, And Checking: A Behind-The-Scenes Look At A Bayesian Analysis Of Arsenic Exposure Pathways, Peter F. Craigmile, Catherine A. Calder, Hongfei Li, Rajib Paul, Noel Cressie Nov 2012

Hierarchical Model Building, Fitting, And Checking: A Behind-The-Scenes Look At A Bayesian Analysis Of Arsenic Exposure Pathways, Peter F. Craigmile, Catherine A. Calder, Hongfei Li, Rajib Paul, Noel Cressie

Professor Noel Cressie

In this article, we present a behind-the-scenes look at a Bayesian hierarchical analysis of pathways of exposure to arsenic (a toxic heavy metal) using the Phase I National Human Exposure Assessment Survey carried out in Arizona. Our analysis combines individual-level personal exposure measurements (biomarker and environmental media) with water, soil, and air observations from the ambient environment. We include details of our model-building exercise that involved a combination of exploratory data analysis and substantive knowledge in exposure science. Then we present our strategies for model fitting, which involved piecing together components of the hierarchical model in a systematic fashion to …


Accounting For Uncertainty In Ecological Analysis: The Strengths And Limitations Of Hierarchical Statistical Modeling, Noel Cressie, Catherine Calder, James Clark, Jay Ver Hoef, Christopher Wikle Nov 2012

Accounting For Uncertainty In Ecological Analysis: The Strengths And Limitations Of Hierarchical Statistical Modeling, Noel Cressie, Catherine Calder, James Clark, Jay Ver Hoef, Christopher Wikle

Professor Noel Cressie

Analyses of ecological data should account for the uncertainty in the process(es) that generated the data. However, accounting for these uncertainties is a difficult task, since ecology is known for its complexity. Measurement and/or process errors are often the only sources of uncertainty modeled when addressing complex ecological problems, yet analyses should also account for uncertainty in sampling design, in model specification, in parameters governing the specified model, and in initial and boundary conditions. Only then can we be confident in the scientific inferences and forecasts made from an analysis. Probability and statistics provide a framework that accounts for multiple …


Security Analysis Of Michael: The Ieee 802.11i Message Integrity Code, Jianyong Huang, Jennifer Seberry, Willy Susilo, Martin W. Bunder Nov 2012

Security Analysis Of Michael: The Ieee 802.11i Message Integrity Code, Jianyong Huang, Jennifer Seberry, Willy Susilo, Martin W. Bunder

Dr Martin Bunder

The latest IEEE 802.11i uses a keyed hash function, called Michael, as the message integrity code. This paper describes some properties and weaknesses of Michael. We provide a necessary and sufficient condition for finding collisions of Michael. Our observation reveals that the collision status of Michael only depends on the second last block message and the output of the block function in the third last round. We show that Michael is not collision-free by providing a method to find collisions of this keyed hash function. Moreover, we develop a method to find fixed points of Michael. If the output of …


Multivariate Whole Genome Average Interval Mapping: Qtl Analysis For Multiple Traits And/Or Environments, Arunas P. Verbyla, Brian R. Cullis Nov 2012

Multivariate Whole Genome Average Interval Mapping: Qtl Analysis For Multiple Traits And/Or Environments, Arunas P. Verbyla, Brian R. Cullis

Professor Brian Cullis

A major aim in some plant-based studies is the determination of quantitative trait loci (QTL) for multiple traits or across multiple environments. Understanding these QTL by trait or QTL by environment interactions can be of great value to the plant breeder. A whole genome approach for the analysis of QTL is presented for such multivariate applications. The approach is an extension of whole genome average interval mapping in which all intervals on a linkage map are included in the analysis simultaneously. A random effects working model is proposed for the multivariate (trait or environment) QTL effects for each interval, with …


The Design And Analysis Of Multi-Phase Plant Breeding Experiments, A B. Smith, P Lim, Brian R. Cullis Nov 2012

The Design And Analysis Of Multi-Phase Plant Breeding Experiments, A B. Smith, P Lim, Brian R. Cullis

Professor Brian Cullis

Despite the importance of selection for quality characteristics in plant improvement programmes, literature on experimental design and statistical analysis for these traits is scarce. Most quality traits are obtained from multi-phase experiments in which plant varieties are first grown in a field trial then further processed in the laboratory. In the present paper a general mixed model approach for the analysis of multi-phase data is described, with particular emphasis on quality trait data that are often highly unbalanced and involve substantial sources of non-genetic variation and correlation. Also detailed is a new approach for experimental design that employs partial replication …


On The Analysis Of Background Subtraction Techniques Using Gaussian Mixture Models, Abdesselam Bouzerdoum, Azeddine Beghdadi, Son Lam Phung, Philippe L. Bouttefroy Nov 2012

On The Analysis Of Background Subtraction Techniques Using Gaussian Mixture Models, Abdesselam Bouzerdoum, Azeddine Beghdadi, Son Lam Phung, Philippe L. Bouttefroy

Professor Salim Bouzerdoum

In this paper, we conduct an investigation into background subtraction techniques using Gaussian Mixture Models (GMM) in the presence of large illumination changes and background variations. We show that the techniques used to date suffer from the trade-off imposed by the use of a common learning rate to update both the mean and variance of the component densities, which leads to a degeneracy of the variance and creates “saturated pixels”. To address this problem, we propose a simple yet effective technique that differentiates between the two learning rates, and imposes a constraint on the variance so as to avoid the …


The Fourier Spectrum Analysis Of Optical Feedback Self-Mixing Signal Under Weak And Moderate Feedback, Xiaojun Zhang, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo Nov 2012

The Fourier Spectrum Analysis Of Optical Feedback Self-Mixing Signal Under Weak And Moderate Feedback, Xiaojun Zhang, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo

Professor Joe F. Chicharo

The spectrum characteristics of self-mixing signals observed in optical feedback self-mixing interferometry (OFSMI) is studied in this paper. The purpose is to provide guidance for the design of pre-processing techniques for eliminating noise or disturbance. The influence of two important parameters of the OFSMI system on the spectrum, that is, the optical feedback factor and the linewidth enhancment factor, are measured by means of Discrete Fourier transform (DFT). The simulated results show that, at a weak feedback, the OFSMI signals are strictly band limited in nature, with the cut-off frequencies being the vibration frequency and the fringe frequency respectively. Also …