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Full-Text Articles in Physical Sciences and Mathematics

Towards The Right Ordering Of The Sequence Of Models For The Evolution Of A Population Using Agent-Based Simulation, Morgane Dumont, Johan Barthelemy, Nam N. Huynh, Timoteo Carletti Jan 2018

Towards The Right Ordering Of The Sequence Of Models For The Evolution Of A Population Using Agent-Based Simulation, Morgane Dumont, Johan Barthelemy, Nam N. Huynh, Timoteo Carletti

SMART Infrastructure Facility - Papers

Agent based modelling is nowadays widely used in transport and the social science. Forecasting population evolution and analysing the impact of hypothetical policies are often the main goal of these developments. Such models are based on sub-models defining the interactions of agents either with other agents or with their environment. Sometimes, several models represent phenomena arising at the same time in the real life. Hence, the question of the order in which these sub-models need to be applied is very relevant for simulation outcomes. This paper aims to analyse and quantify the impact of the change in the order of …


The Potential Of Induced Pluripotent Stem Cells In Models Of Neurological Disorders: Implications On Future Therapy, Jeremy M. Crook, Gordon G. Wallace, Eva Tomaskovic-Crook Jan 2015

The Potential Of Induced Pluripotent Stem Cells In Models Of Neurological Disorders: Implications On Future Therapy, Jeremy M. Crook, Gordon G. Wallace, Eva Tomaskovic-Crook

Australian Institute for Innovative Materials - Papers

There is an urgent need for new and advanced approaches to modeling the pathological mechanisms of complex human neurological disorders. This is underscored by the decline in pharmaceutical research and development efficiency resulting in a relative decrease in new drug launches in the last several decades. Induced pluripotent stem cells represent a new tool to overcome many of the shortcomings of conventional methods, enabling live human neural cell modeling of complex conditions relating to aberrant neurodevelopment, such as schizophrenia, epilepsy and autism as well as age-associated neurodegeneration. This review considers the current status of induced pluripotent stem cell-based modeling of …


Eliciting Mental Models: A Comparison Of Interview Procedures In The Context Of Natural Resource Management, Natalie A. Jones, Helen Ross, Timothy Lynam, Pascal Perez Jan 2014

Eliciting Mental Models: A Comparison Of Interview Procedures In The Context Of Natural Resource Management, Natalie A. Jones, Helen Ross, Timothy Lynam, Pascal Perez

SMART Infrastructure Facility - Papers

The sustainable management of natural resources largely depends on people's conceptions of environmental systems and how they function. The mental model construct provides an appropriate means to explore the cognitive dimension of people's interactions with such systems. Mental models are cognitive representations of external reality that people use as the basis for acting with and within the world around them. We aimed to improve the application of the mental model construct to the field of natural resource management, with an emphasis on creek, i.e., stream, systems, by exploring how certain elicitation procedures may affect the mental models expressed. One of …


Process-Evaluation Of Tropospheric Humidity Simulated By General Circulation Models Using Water Vapor Isotopologues: 1. Comparison Between Models And Observations, Camille Risi, David Noone, John Worden, Christian Frankenberg, Gabriele Stiller, Michael Kiefer, Bernd Funke, Kaley Walker, Peter Bernath, Matthias Schneider, Debra Wunch, Vanessa Sherlock, Nicholas M. Deutscher, David W. Griffith, Paul O. Wennberg, Kimberly Strong, Dan Smale, Emmanuel Mahieu, Sabine Barthlott, Frank Hase, Omar Garcia, Justus Notholt, Thorsten Warneke, Geoffrey Toon, David Sayres, Sandrine Bony, Jeonghoon Lee, Derek Brown, Ryu Uemura, Christophe Sturm Mar 2012

Process-Evaluation Of Tropospheric Humidity Simulated By General Circulation Models Using Water Vapor Isotopologues: 1. Comparison Between Models And Observations, Camille Risi, David Noone, John Worden, Christian Frankenberg, Gabriele Stiller, Michael Kiefer, Bernd Funke, Kaley Walker, Peter Bernath, Matthias Schneider, Debra Wunch, Vanessa Sherlock, Nicholas M. Deutscher, David W. Griffith, Paul O. Wennberg, Kimberly Strong, Dan Smale, Emmanuel Mahieu, Sabine Barthlott, Frank Hase, Omar Garcia, Justus Notholt, Thorsten Warneke, Geoffrey Toon, David Sayres, Sandrine Bony, Jeonghoon Lee, Derek Brown, Ryu Uemura, Christophe Sturm

Faculty of Science - Papers (Archive)

[1] The goal of this study is to determine how H2O and HDO measurements in water vapor can be used to detect and diagnose biases in the representation of processes controlling tropospheric humidity in atmospheric general circulation models (GCMs). We analyze a large number of isotopic data sets (four satellite, sixteen ground-based remote-sensing, five surface in situ and three aircraft data sets) that are sensitive to different altitudes throughout the free troposphere. Despite significant differences between data sets, we identify some observed HDO/H2O characteristics that are robust across data sets and that can be used to evaluate models. We evaluate …


Evaluating The Volatility Forecasting Performance Of Best Fitting Garch Models In Emerging Asian Stock Markets, Chaiwat Kosapattarapim, Yan-Xia Lin, Michael Mccrae Jan 2012

Evaluating The Volatility Forecasting Performance Of Best Fitting Garch Models In Emerging Asian Stock Markets, Chaiwat Kosapattarapim, Yan-Xia Lin, Michael Mccrae

Faculty of Informatics - Papers (Archive)

While modeling the volatility of returns is essential for many areas of finance, it is well known that financial return series exhibit many non-normal characteristics that cannot be captured by the standard GARCH model with a normal error distribution. But which GARCH model and which error distribution to use is still open to question, especially where the model that best fits the in-sample data may not give the most effective out-of-sample volatility forecasting ability. Approach: In this study, six simulated studies in GARCH(p,q) with six different error distributions are carried out. In each case, we determine the best fitting GARCH …


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 Jan 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

Faculty of Informatics - Papers (Archive)

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 …


A Simple Post-Hoc Method To Add Spatial Context To Predictive Species Distribution Models, Michael B. Ashcroft, Kristine O. French, Laurie A. Chisholm Jan 2012

A Simple Post-Hoc Method To Add Spatial Context To Predictive Species Distribution Models, Michael B. Ashcroft, Kristine O. French, Laurie A. Chisholm

Faculty of Science - Papers (Archive)

Methods to incorporate spatial context into species distribution models (SDMs) are underutilised, with predictions usually based only on environmental space and ignoring geographic space. The goals of this study were to demonstrate a relatively simple post-hoc method to include spatial context in SDMs and to quantify the improvement over purely niche-based models. The method involved producing a standard niche-based model using established techniques, such as Maxent, and then calculating the neighbourhood average of the model output in geographic space. In effect, we tested whether the spatially averaged model output was better at predicting species distributions than the raw model output. …


A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Tessier Kinetics, M I. Nelson, E Balakrishnan, H S. Sidhu Jan 2012

A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Tessier Kinetics, M I. Nelson, E Balakrishnan, H S. Sidhu

Faculty of Informatics - Papers (Archive)

In this research we analyze the steady-state operation of a continuous flow bioreactor, with or without recycle, and an idealized or nonidealized continuous flow membrane reactor. The model extends to include a fixed bed reactor where a fraction of the biomass is detached by the flow. The reaction is assumed to be governed by Tessier growth kinetics. We show that a flow reactor with idealized recycle has the same performance as an idealized membrane reactor and that the performance of a nonidealized membrane reactor is identical to that of an appropriately defined continuous flow bioreactor with nonidealized recycle. The performance …


Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez Jan 2012

Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez

SMART Infrastructure Facility - Papers

Although the broad concept of mental models is gaining currency as a way to explore the link between how people think and interact with their world, this concept is limited by a theoretical and practical understanding of how it can be applied in the study of human-environment relationships. Tools and processes are needed to be able to elicit and analyze mental models. Because mental models are not directly observable, it is also important to understand how the application of any tools and processes affects what is measured. Equally important are the needs to be clear on the intent of the …


A Spatial Analysis Of Multivariate Output From Regional Climate Models, Stephan Sain, Reinhard Furrer, Noel A. Cressie Jan 2011

A Spatial Analysis Of Multivariate Output From Regional Climate Models, Stephan Sain, Reinhard Furrer, Noel A. Cressie

Faculty of Informatics - Papers (Archive)

Climate models have become an important tool in the study of climate and climate change, and ensemble experiments consisting of multiple climate-model runs are used in studying and quantifying the uncertainty in climate-model output. However, there are often only a limited number of model runs available for a particular experiment, and one of the statistical challenges is to characterize the distribution of the model output. To that end, we have developed a multivariate hierarchical approach, at the heart of which is a new representation of a multivariate Markov random field. This approach allows for flexible modeling of the multivariate spatial …


Initial Values In Estimation Procedures For State Space Models (Ssms), Raed Alzghool, Yan-Xia Lin Jan 2011

Initial Values In Estimation Procedures For State Space Models (Ssms), Raed Alzghool, Yan-Xia Lin

Faculty of Informatics - Papers (Archive)

In this paper, we will focus on State Space Models(SSMs), especially the stochastic volatility model, and lookfor a standard approach for assigning initial values in theQuasi-Likelihood (QL) and Asymptotic Quasi-Likelhood (AQL)estimation procedures.


Pricing Of Volatility Derivatives Using 3/2-Stochastic Models, Joanna Goard Jan 2011

Pricing Of Volatility Derivatives Using 3/2-Stochastic Models, Joanna Goard

Faculty of Informatics - Papers (Archive)

Analytic solutions are found for prices of both variance and volatility swaps and VIX options under new 3/2- stochastic models for the dynamics of the underlying assets. The main features of the new stochastic differential equations are an empirically validated cv3/2 diffusion term, a nonlinear drift providing a balancing effect of a stronger mean reversion with high volatility, and for the case of the variance and volatility swaps, a free function of time as a moving target in the reversion term, allowing additional flexibility for model calibration against market data.


Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang Jan 2011

Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang

Faculty of Informatics - Papers (Archive)

Vehicle seat suspension is one of very important components to provide ride comfort, in particular, commercial vehicles, to reduce driver fatigue due to long hours driving. This paper presents a study on active control of seat suspension to reduce vertical vibration transmitted from uneven road profile to driver body. The control problem will be firstly studied by proposing an integrated seat suspension model which includes vehicle chassis suspension, seat suspension, and driver body model. This is a new concept in the field of study because most of the current active and semi-active seat suspension studies only consider seat suspension or …


A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark I. Nelson, Annette L. Worthy Jan 2011

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

Faculty of Informatics - Papers (Archive)

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. …


Some Mathematical Models Arising In Nano- And Bio-Technology, Yue Chan Jan 2010

Some Mathematical Models Arising In Nano- And Bio-Technology, Yue Chan

Faculty of Informatics - Papers (Archive)

In this thesis, three mechanical models arising from nanoscale and biological systems are investigated, namely the dynamics of various nanostructures, the axial buckling of carbon nanotubes and nanopeapods, and the worm-like chain model for stretched semi-flexible molecules and the utilization of such a model for investigating molecular stretching in the connective tissue extracellular matrix.


On The Analysis Of Background Subtraction Techniques Using Gaussian Mixture Models, Abdesselam Bouzerdoum, Azeddine Beghdadi, Son Lam Phung, Philippe L. Bouttefroy Jan 2010

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

Faculty of Informatics - Papers (Archive)

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 …


Relative Importance Of Fuel Management, Ignition Management And Weather For Area Burned: Evidence From Five Landscape-Fire-Succession Models, Geoffrey J. Cary, Mike D. Flannigan, Robert E. Keane, Ross A. Bradstock, Ian D. Davies, James M. Lenihan, Chao Li, Kimberley A. Logan, Russell A. Parsons Jan 2009

Relative Importance Of Fuel Management, Ignition Management And Weather For Area Burned: Evidence From Five Landscape-Fire-Succession Models, Geoffrey J. Cary, Mike D. Flannigan, Robert E. Keane, Ross A. Bradstock, Ian D. Davies, James M. Lenihan, Chao Li, Kimberley A. Logan, Russell A. Parsons

Faculty of Science - Papers (Archive)

The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEM-LAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets adjacent to fire-prone landscapes) was quantified for a standardised modelling landscape. Importance was measured as the proportion of variation in area or edge pixels burned explained by each factor and all interactions among them. Weather and ignition management were consistently more important for explaining variation in area …


Stable Isotope Metabolic Labeling With A Novel 15n-Enriched Bacteria Diet For Improved Proteomic Analyses Of Mouse Models For Psychopathologies, Yinglong Zhang, Elisabeth T. Frank, B. Hambsch, C. W. Turck, M. Bunck, R. Landgraf, M. S. Kessler, G. Maccarrone, M. Filiou, Hermann Heumann, Stefan Reckow Jan 2009

Stable Isotope Metabolic Labeling With A Novel 15n-Enriched Bacteria Diet For Improved Proteomic Analyses Of Mouse Models For Psychopathologies, Yinglong Zhang, Elisabeth T. Frank, B. Hambsch, C. W. Turck, M. Bunck, R. Landgraf, M. S. Kessler, G. Maccarrone, M. Filiou, Hermann Heumann, Stefan Reckow

Faculty of Science - Papers (Archive)

The identification of differentially regulated proteins in animal models of psychiatric diseases is essential for a comprehensive analysis of associated psychopathological processes. Mass spectrometry is the most relevant method for analyzing differences in protein expression of tissue and body fluid proteomes. However, standardization of sample handling and sample-to-sample variability are problematic. Stable isotope metabolic labeling of a proteome represents the gold standard for quantitative mass spectrometry analysis. The simultaneous processing of a mixture of labeled and unlabeled samples allows a sensitive and accurate comparative analysis between the respective proteomes. Here, we describe a cost-effective feeding protocol based on a newly …


Formative Versus Reflective Measurement Models: Two Applications Of Formative Measurement, T. Coltman, T. M. Devinney, D. F. Midgley, S. Venaik Jan 2008

Formative Versus Reflective Measurement Models: Two Applications Of Formative Measurement, T. Coltman, T. M. Devinney, D. F. Midgley, S. Venaik

Faculty of Informatics - Papers (Archive)

This paper presents a framework that helps researchers to design and validate both formative and reflective measurement models. The framework draws from the existing literature and includes both theoretical and empirical considerations. Two important examples, one from international business and one from marketing, illustrate the use of the framework. Both examples concern constructs that are fundamental to theory-building in these disciplines, and constructs that most scholars measure reflectively. In contrast, applying the framework suggests that a formative measurement model may be more appropriate. These results reinforce the need for all researchers to justify, both theoretically and empirically, their choice of …


Can Superior Crm Capabilities Improve Performance In Banking, T. R. Coltman Nov 2007

Can Superior Crm Capabilities Improve Performance In Banking, T. R. Coltman

Faculty of Informatics - Papers (Archive)

The market enthusiasm generated around investment in customer relationship management (CRM) technology is in stark contrast to the nay-saying by many academic and business commentators. This raises an important research question concerning the extent to which banks should continue to invest in CRM technology. Drawing on field interviews and a survey of senior bank executives the results reveal that a superior CRM capability can deliver improved performance. The paper then demonstrates that in order to be most successful, CRM programs require a combination of technical, human and business capabilities.


Flexible Spatial Models For Kriging And Cokriging Using Moving Averages And The Fast Fourier Transform (Fft), Jay M. Ver Hoef, Noel A. Cressie, Ronald P. Barry Jan 2004

Flexible Spatial Models For Kriging And Cokriging Using Moving Averages And The Fast Fourier Transform (Fft), Jay M. Ver Hoef, Noel A. Cressie, Ronald P. Barry

Faculty of Informatics - Papers (Archive)

Models for spatial autocorrelation and cross-correlation depend on the distance and direction separating two locations, and are constrained so that for all possible sets of locations, the covariance matrices implied from the models remain nonnegative-definite. Based on spatial correlation, optimal linear predictors can be constructed that yield complete maps of spatial fields from incomplete and noisy spatial data. This methodology is called kriging if the data are of only one variable type, and it is called cokriging if it is of two or more variable types. Historically, to satisfy the nonnegative-definite condition, cokriging has used coregionalization models for cross-variograms, even …


Charge-On-Spring Polarizable Water Models Revisited: From Water Clusters To Liquid Water To Ice, Haibo Yu, Wilfred Van Gunsteren Jan 2004

Charge-On-Spring Polarizable Water Models Revisited: From Water Clusters To Liquid Water To Ice, Haibo Yu, Wilfred Van Gunsteren

Faculty of Science - Papers (Archive)

The properties of two improved versions of charge-on-spring �COS� polarizable water models (COS/G2 and COS/G3) that explicitly include nonadditive polarization effects are reported. In COS models, the polarization is represented via a self-consistently induced dipole moment consisting of a pair of separated charges. A previous polarizable water model (COS/B2), upon which the improved versions are based, was developed by Yu, Hansson, and van Gunsteren �J. Chem. Phys. 118, 221 �2003��. To improve the COS/B2 model, which overestimated the dielectric permittivity, one additional virtual atomic site was used to reproduce the water monomer quadrupole moments besides the water monomer dipole moment …


Size And Power Considerations For Testing Loglinear Models Using Divergence Test Statistics, Noel A. Cressie, L Pardo, M Del Carmen Pardo Jan 2003

Size And Power Considerations For Testing Loglinear Models Using Divergence Test Statistics, Noel A. Cressie, L Pardo, M Del Carmen Pardo

Faculty of Informatics - Papers (Archive)

In this article, we assume that categorical data are distributed according to a multinomial distribution whose probabilities follow a loglinear model. The inference problem we consider is that of hypothesis testing in a loglinear-model setting. The null hypothesis is a composite hypothesis nested within the alternative. Test statistics are chosen from the general class of divergence statistics. This article collects together the operating characteristics of the hypothesis test based on both asymptotic (using large-sample theory) and finite-sample (using a designed simulation study) results. Members of the class of power divergence statistics are compared, and it is found that the Cressie-Read …


Spatial Mixture Models Based On Exponential Family Conditional Distributions, M Kaiser, Noel A. Cressie, J Lee Jan 2002

Spatial Mixture Models Based On Exponential Family Conditional Distributions, M Kaiser, Noel A. Cressie, J Lee

Faculty of Informatics - Papers (Archive)

Spatial statistical models are applied in many problems for which dependence in observed random variables is not easily explained by a direct scientific mechanism. In such situations there may be a latent spatial process that acts to produce the observed spatial pattern. Scientific interest often centers on the latent process and the degree of spatial dependence that characterizes it. Such latent processes may be thought of as spatial mixing distributions. We present methods for the specification of flexible joint distributions to model spatial processes through multi-parameter exponential family conditional distributions. One approach to the analysis of these models is Monte …


Models For Genesis Of Kamchatka Are Magmas: New Insights From U-Series, Anthony Dosseto, Bernard Bourdon Jan 2002

Models For Genesis Of Kamchatka Are Magmas: New Insights From U-Series, Anthony Dosseto, Bernard Bourdon

Faculty of Science - Papers (Archive)

No abstract provided.


Asymptotic Properties Of Maximum (Composite) Likelihood Estimators For Partially Ordered Markov Models, Hsin-Cheng Huang, Noel A. Cressie Jan 2000

Asymptotic Properties Of Maximum (Composite) Likelihood Estimators For Partially Ordered Markov Models, Hsin-Cheng Huang, Noel A. Cressie

Faculty of Informatics - Papers (Archive)

Partially ordered Markov models (POMMs) are Markov random fields (MRFs) with neighborhood structures derivable from an associated partially ordered set. The most attractive feature of POMMs is that their joint distributions can be written in closed and product form. Therefore, simulation and maximum likelihood estimation for the models is quite straightforward, which is not the case in general for MRF models. In practice, one often has to modify the likelihood to account for edge components; the resulting composite likelihood for POMMs is similarly straightforward to maximize. In this article, we use a martingale approach to derive the asymptotic properties of …


Minimum Phi Divergence Estimator And Hierarchical Testing In Loglinear Models, Noel A. Cressie, Leandro Pardo Jan 2000

Minimum Phi Divergence Estimator And Hierarchical Testing In Loglinear Models, Noel A. Cressie, Leandro Pardo

Faculty of Informatics - Papers (Archive)

In this paper we consider inference based on very general divergence measures, under assumptions of multinomial sampling and loglinear models. We define the minimum phi divergence estimator, which is seen to be a generalization of the maximum likelihood estimator. This estimator is then used in a phi divergence goodness-of-fit statistic, which is the basis of two new statistics for solving the problem of testing a nested sequence of loglinear models.


Mine Boundary Detection Using Partially Ordered Markov Models, Xia Hua, Jennifer Davidson, Noel A. Cressie Jan 1997

Mine Boundary Detection Using Partially Ordered Markov Models, Xia Hua, Jennifer Davidson, Noel A. Cressie

Faculty of Informatics - Papers (Archive)

Detection of objects in images in an automated fashion is necessary for many applications, including automated target recognition. In this paper, we present results of an automated boundary detection procedure using a new subclass of Markov random fields (MRFs), called partially ordered Markov models (POMMs). POMMs offer computational advantages over general MRFs. We show how a POMM can model the boundaries in an image. Our algorithm for boundary detection uses a Bayesian approach to build a posterior boundary model that locates edges of objects having a closed loop boundary. We apply our method to images of mines with very good …


Models And Inference For Clustering Of Locations Of Mines And Minelike Objects, Noel A. Cressie, Andrew B. Lawson Jan 1997

Models And Inference For Clustering Of Locations Of Mines And Minelike Objects, Noel A. Cressie, Andrew B. Lawson

Faculty of Informatics - Papers (Archive)

Mines and mine-like objects are distributed throughout an area of interest. Remote sensing of the area form an aircraft yields image data that represent the superposition of electromagnetic emissions from the mines and mine-like objects. In this article we build a hierarchical statistical model for the reconstruction of mien locations given a point pattern of the superposition of mines and mine-like objects. It is shown how inference on the mine locations can be obtained using Markov chain Monte Carlo methods.


Texture Analysis Using Partially Ordered Markov Models, Jennifer Davidson, Ashit Talukder, Noel A. Cressie Jan 1994

Texture Analysis Using Partially Ordered Markov Models, Jennifer Davidson, Ashit Talukder, Noel A. Cressie

Faculty of Informatics - Papers (Archive)

Texture is a phenomenon in image data that continues to receive wide-spread interest due to its broad range of applications. The paper focuses on but one of several ways to model textures, namely, the class of stochastic texture models. the authors introduce a new spatial stochastic model called partially ordered Markov models, or POMMs. They show how POMMs are a generalization of a class of models called Markov mesh models, or MMMs, that allow an explicit closed form of the joint probability, just as do MMMs. While POMMs are a type of Markov random field model (MRF), the general MRFs …