Engineering Commons^™

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 …

Investigation Of Track Structure And Condensed History Physics Models For Applications In Radiation Dosimetry On A Micro And Nano Scale In Geant4, Peter Lazarakis, Sebastien Incerti, Vladimir N. Ivanchenko, Ioanna Kyriakou, Dimitris Emfietzoglou, Stephanie Corde, Anatoly B. Rosenfeld, Michael L. F Lerch, Moeava Tehei, Susanna Guatelli

Faculty of Engineering and Information Sciences - Papers: Part B

Monte Carlo methods apply various physical models, either condensed history (CH) or track structure (TS), to simulate the passage of radiation through matter. Both CH and TS models continue to be applied to radiation dosimetry investigations on a micro and nano scale. However, as there has been no systematic comparison of the use of these models for such applications there can be no quantification of the uncertainty that is being introduced by the choice of physics model. A comparison of CH and TS models available in Geant4, along with a quantification of the differences in calculated quantities on a micro …

Compressive Behaviour Of Partially Frp Confined Concrete: Experimental Observations And Assessment Of The Stress-Strain Models, Weiqiang Wang, M Neaz Sheikh, Ali Qasim Al-Baali, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

This study provides new insight on the compressive behaviour of partially fibre reinforced polymer (FRP) confined concrete with either strain-hardening or strain-softening responses. Fully FRP confined concrete, partially FRP confined concrete with different strip gaps, and unconfined concrete were tested under axial compression. Four types of axial load-axial deformation behaviours were observed for specimens with different strip gaps. Even though a high volumetric ratio of FRP was applied, the confinement effectiveness was negligible when the strip gap exceeded the diameter of the specimens. Moreover, the axial stress-axial strain behaviours of wrapped and non-wrapped concrete were observed to be different, and …

A Comparison Study For Supervised Machine Learning Models In Cancer Classification, Huaming Chen, Hong Zhao, Lei Wang, Jiangning Song, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.

Threat Models For Analyzing Plausible Deniability Of Deniable File Systems, Michal Kedziora, Yang-Wai Chow, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part B

Plausible deniability is a property of Deniable File System (DFS), which are encrypted using a Plausibly Deniable Encryption (PDE) scheme, where one cannot prove the existence of a hidden file system within it. This paper investigates widely used security models that are commonly employed for analyzing DFSs. We contend that these models are no longer adequate considering the changing technological landscape that now encompass platforms like mobile and cloud computing as a part of everyday life. This necessitates a shift in digital forensic analysis paradigms, as new forensic models are required to detect and analyze DFSs. As such, it is …

Sharing Social Network Data: Differentially Private Estimation Of Exponential Family Random-Graph Models, Vishesh Karwa, Pavel N. Krivitsky, Aleksandra B. Slavkovic

Faculty of Engineering and Information Sciences - Papers: Part A

Motivated by a real life problem of sharing social network data that contain sensitive personal information, we propose a novel approach to release and analyse synthetic graphs to protect privacy of individual relationships captured by the social network while maintaining the validity of statistical results. A case-study using a version of the Enron e-mail corpus data set demonstrates the application and usefulness of the proposed techniques in solving the challenging problem of maintaining privacy and supporting open access to network data to ensure reproducibility of existing studies and discovering new scientific insights that can be obtained by analysing such data. …

Using Contrastive Divergence To Seed Monte Carlo Mle For Exponential-Family Random Graph Models, Pavel N. Krivitsky

Faculty of Engineering and Information Sciences - Papers: Part A

Exponential-family models for dependent data have applications in a wide variety of areas, but the dependence often results in an intractable likelihood, requiring either analytic approximation or MCMC-based techniques to fit, the latter requiring an initial parameter configuration to seed their simulations. A poor initial configuration can lead to slow convergence or outright failure. The approximate techniques that could be used to find them tend not to be as general as the simulation-based and require implementation separate from that of the MLE-finding algorithm. Contrastive divergence is a more recent simulation-based approximation technique that uses a series of abridged MCMC runs …

Optimizing Wearable Assistive Devices With Neuromuscular Models And Optimal Control, Manish Sreenivasa, Matthew Millard, Paul Manns, Katja Mombaur

Faculty of Engineering and Information Sciences - Papers: Part B

The coupling of human movement dynamics with the function and design of wearable assistive devices is vital to better understand the interaction between the two. Advanced neuromuscular models and optimal control formulations provide the possibility to study and improve this interaction. In addition, optimal control can also be used to generate predictive simulations that generate novel movements for the human model under varying optimization criterion.

Linear Regression Models For Prediction Of Annual Heating And Cooling Demand In Representative Australian Residential Dwellings, Navid Aghdaei, Georgios Kokogiannakis, Daniel J. Daly, Timothy J. Mccarthy

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents the development methodology of linear regression models that were developed for the prediction of annual thermal loads in representative residential buildings across three major climates in New South Wales, Australia, and the assessment of the impact of building envelope upgrades. A differential sensitivity analysis was undertaken for sixteen building envelope parameters, with six parameters being identified as significant. These six parameters were then explored using EnergyPlus simulation, and a number of linear regression models developed from the simulation outputs. Random values for design parameters were generated, and the results of EnergyPlus simulations using these parameters were used …

Joint Pet-Mr Respiratory Motion Models For Clinical Pet Motion Correction, Richard Manber, Kris Thielemans, Brian F. Hutton, Simon Wan, Jamie Mcclelland, Anna Barnes, Simon R. Arridge, Sebastien Ourselin, David Atkinson

Faculty of Engineering and Information Sciences - Papers: Part A

Patient motion due to respiration can lead to artefacts and blurring in positron emission tomography (PET) images, in addition to quantification errors. The integration of PET with magnetic resonance (MR) imaging in PET-MR scanners provides complementary clinical information, and allows the use of high spatial resolution and high contrast MR images to monitor and correct motion-corrupted PET data. In this paper we build on previous work to form a methodology for respiratory motion correction of PET data, and show it can improve PET image quality whilst having minimal impact on clinical PET-MR protocols. We introduce a joint PET-MR motion model, …

Interaction Prediction Between Groundwater And Quarry Extension Using Discrete Choice Models And Artificial Neural Networks, Johan Barthelemy, Timoteo Carletti, Louise Collier, Vincent Hallet, Marie Moriame, Annick Sartenear

Faculty of Engineering and Information Sciences - Papers: Part A

Groundwater and rock are intensively exploited in the world. When a quarry is deepened the water table of the exploited geological formation might be reached. A dewatering system is therefore installed so that the quarry activities can continue, possibly impacting the nearby water catchments. In order to recommend an adequate feasibility study before deepening a quarry, we propose two interaction indices between extractive activity and groundwater resources based on hazard and vulnerability parameters used in the assessment of natural hazards. The levels of each index (low, medium, high, very high) correspond to the potential impact of the quarry on the …

An Implementation Of Discrete Electron Transport Models For Gold In The Geant4 Simulation Toolkit, D Sakata, Sebastien Incerti, M Bordage, N Lampe, Susumu Okada, Dimitris Emfietzoglou, Ioanna Kyriakou, K Murakami, Takashi Sasaki, H Tran, Susanna Guatelli, V Ivantchenko

Faculty of Engineering and Information Sciences - Papers: Part A

Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. …

Flexible Analysis Of Digital Pcr Experiments Using Generalized Linear Mixed Models, Matthijs Vynck, J Vandesompele, Nele Nijs, Björn Menten, Ariane De Ganck, Olivier Thas

Faculty of Engineering and Information Sciences - Papers: Part A

The use of digital PCR for quantification of nucleic acids is rapidly growing. A major drawback remains the lack of flexible data analysis tools. Published analysis approaches are either tailored to specific problem settings or fail to take into account sources of variability. We propose the generalized linear mixed models framework as a flexible tool for analyzing a wide range of experiments. We also introduce a method for estimating reference gene stability to improve accuracy and precision of copy number and relative expression estimates. We demonstrate the usefulness of the methodology on a complex experimental setup.

Factor Analytic Mixed Models For The Provision Of Grower Information From National Crop Variety Testing Programs, Alison B. Smith, Aanandini Ganesalingam, Haydn Kuchel, Brian R. Cullis

Faculty of Engineering and Information Sciences - Papers: Part A

Crop variety testing programs are conducted in many countries world-wide. Within each program, data are combined across locations and seasons, and analysed in order to provide information to assist growers in choosing the best varieties for their conditions. Despite major advances in the statistical analysis of multi-environment trial data, such methodology has not been adopted within national variety testing programs. The most commonly used approach involves a variance component model that includes variety and environment main effects, and variety by environment ( VxE ) interaction effects. The variety predictions obtained from such an analysis, and subsequently reported to growers, are …

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 …

Calibrating Markov Chain-Based Deterioration Models For Predicting Future Conditions Of Railway Bridge Elements, Niroshan Walgama Wellalage, Tieling Zhang, Richard Dwight

Faculty of Engineering and Information Sciences - Papers: Part A

Existing nonlinear optimization-based algorithms for estimating Markov transition probability matrix (TPM) in bridge deterioration modeling sometimes fail to find optimum TPM values, and hence lead to invalid future condition prediction. In this study, a Metropolis-Hasting algorithm (MHA)-based Markov chain Monte Carlo (MCMC) simulation technique is proposed to overcome this limitation and calibrate the state-based Markov deterioration models (SBMDM) of railway bridge components. Factors contributing to rail bridge deterioration were identified; inspection data for 1,000 Australian railway bridges over 15 years were reviewed and filtered. The TPMs corresponding to a typical bridge element were estimated using the proposed MCMC simulation method …

Inconsistency Resolution In Merging Versions Of Architectural Models, Hoa Dam, Alexander Reder, Alexander Egyed

Faculty of Engineering and Information Sciences - Papers: Part A

State-of-the-art optimistic model versioning systems, which are critical to enable efficient team-based development of architectural models, are able to detect and help resolve basic conflicts arising during the merging of model versions. However, it is often overlooked that model merging may also cause severe syntactical and semantic inconsistencies. In this paper, we propose an approach to guide the resolution of inconsistencies detected in a merged architectural model. Our approach automatically finds and presents to the software architects all solutions for resolving all inconsistencies arisen during the merging of model versions. For inconsistencies that preexist in the model, our approach is …

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 …

Elastic Models For Nonlinear Response Of Rigid Passive Piles, Wei Dong Guo

Faculty of Engineering and Information Sciences - Papers: Part A

Recent study indicates that the response of rigid passive piles is dominated by elastic pile–soil interaction and may be estimated using theory for lateral piles. The difference lies in that passive piles normally are associated with a large scatter of the ratio of maximum bending moment over maximum shear force and induce a limiting pressure that is ~1/3 that on laterally loaded piles. This disparity prompts this study.

This paper proposes pressure-based pile–soil models and develops their associated solutions to capture response of rigid piles subjected to soil movement. The impact of soil movement was encapsulated into a power-law distributed …

A Study On The Suitability Of Cable Models To Simulate Switching Transients In A 132 Kv Underground Cable, Muhamad Zalani Daud, P Ciufo, S Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Switching transients resulting from the energisation of high voltage cable systems may have a significant effect on both the cables being switched as well as the power system components in the vicinity. The impacts of these transients on such cables are measured based on the stress arising as a result of the voltage and current peaks and the frequency of oscillatory transients. These quantities are typically obtained from a simulation by using a suitable cable model, normally with the capability to predict the transient behaviour in the range up to several 10 kHz. To obtain a cable model that enables …

Stochastic Volatility Models And The Pricing Of Vix Options, Joanna Goard, Mathew Mazur

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper we examine and compare the performance of a variety of continuous- time volatility models in their ability to capture the behaviour of the VIX. The `3/2- model' with a di®usion structure which allows the volatility of volatility changes to be highly sensitive to the actual level of volatility is found to outperform all other popular models tested. Analytic solutions for option prices on the VIX under the 3/2- model are developed and then used to calibrate at-the-money market option prices.

Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola

Faculty of Engineering and Information Sciences - Papers: Part A

Wind power generation has indicated an exponential increase during last two decades and existing transmission network infrastructure is increasingly becoming inadequate to transmit remotely generated wind power to load centres in the network. The dynamic line rating (DLR) is one of the viable solutions to improve the transmission line ampacity during high wind penetration without investing on an additional transmission network. The main objective of this study is to identify the basic differences between two main line rating standards, since transmission network service providers (TNSPs) heavily depend on these two standards when developing their line rating models. Therefore, a parameter …

Exact Travelling Wave Solutions For Some Important Nonlinear Physical Models, Jonu Lee, Rathinasamy Sakthivel

Faculty of Engineering and Information Sciences - Papers: Part A

The two-dimensional nonlinear physical models and coupled nonlinear systems such as Maccari equations, Higgs equations and Schrodinger-KdV equations have been widely applied in many branches of physics. So, finding exact travelling wave solutions of such equations are very helpful in the theories and numerical studies. In this paper, the Kudryashov method is used to seek exact travelling wave solutions of such physical models. Further, three-dimensional plots of some of the solutions are also given to visualize the dynamics of the equations. The results reveal that the method is a very effective and powerful tool for solving nonlinear partial differential equations …

Essential Elements In Tactical Planning Models For Container Liner Shipping, Shuaian Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Tactical planning models for liner shipping problems such as network design and fleet deployment usually minimize the total cost or maximize the total profit subject to constraints including ship availability, service frequency, ship capacity, and transshipment. Most models in the literature do not consider slot-purchasing, multi-type containers, empty container repositioning, or ship repositioning, and they formulate the numbers of containers to transport as continuous variables. This paper develops a mixed-integer linear programming model that captures all these elements. It further examines from the theoretical point of view the additional computational burden introduced by incorporating these elements in the planning model. …

Compare Pilot-Scale And Industry-Scale Models Of Pulverized Coal Combustion In An Ironmaking Blast Furnace, Yansong Shen, Aibing Yu, Paul Zulli

Faculty of Engineering and Information Sciences - Papers: Part A

In order to understand the complex phenomena of pulverized coal injection (PCI) process in blast furnace (BF), mathematical models have been developed at different scales: pilot-scale model of coal combustion and industry-scale model (in-furnace model) of coal/coke combustion in a real BF respectively. This paper compares these PCI models in aspects of model developments and model capability. The model development is discussed in terms of model formulation, their new features and geometry/regions considered. The model capability is then discussed in terms of main findings followed by the model evaluation on their advantages and limitations. It is indicated that these PCI …

Class A Prediction Of A Piled Relieving Slab Using Uncoupled Models, David Oliveira, Dan Gorman, Frances Badelow

Faculty of Engineering - Papers (Archive)

Construction of the new Windsor Road on/off ramps, part of the M2 Upgrade project, required limiting the loads and movements imposed on existing precast concrete walls so that no additional pressure was applied as a result of the new construction works. This was necessary due to possible structural deficiencies of some of the existing reinforced concrete elements. A piled relieving slab was adopted as the final solution to support the reinforced soil wall ramps and a comprehensive soil-structure interaction assessment was carried out in order to predict the pile head deflections and assess potential loading of the existing walls. A …

Robust Designs For Poisson Regression Models, J M. Mcgree, J A. Eccleston

Faculty of Engineering and Information Sciences - Papers: Part A

We consider the problem of how to construct robust designs for Poisson regression models. An analytical expression is derived for robust designs for first-order Poisson regression models where uncertainty exists in the prior parameter estimates. Given cer- tain constraints in the methodology, it may be necessary to extend the robust designs for implementation in practical experiments. With these extensions, our methodology con- structs designs which perform similarly, in terms of estimation, to current techniques, and offers the solution in a more timely manner. We further apply this analytic result to cases where uncertainty exists in the linear predictor. The application …

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 …

Marginalized Exponential Random Graph Models, Thomas F. Suesse

Faculty of Engineering and Information Sciences - Papers: Part A

Exponential random graph models (ERGMs) are a popular tool for modeling social networks representing relational data, such as working relationships or friendships. Data on exogenous variables relating to participants in the network, such as gender or age, are also often collected. ERGMs allow modeling of the effects of such exogenous variables on the joint distribution, specified by the ERGM, but not on the marginal probabilities of observing a relationship. In this article, we consider an approach to modeling a network that uses an ERGM for the joint distribution of the network, but then marginally constrains the fit to agree with …

Estimation Of Breeding Values For Mean And Dispersion, Their Variance And Correlation Using Double Hierarchical Generalized Linear Models, M Felleki, D Lee, Y Lee, A R. Gilmour, L Ronnegard

Faculty of Engineering and Information Sciences - Papers: Part A

The possibility of breeding for uniform individuals by selecting animals expressing a small response to environment has been studied extensively in animal breeding. Bayesian methods for fitting models with genetic components in the residual variance have been developed for this purpose, but have limitations due to the computational demands. We use the hierarchical (h)-likelihood from the theory of double hierarchical generalized linear models (DHGLM) to derive an estimation algorithm that is computationally feasible for large datasets. Random effects for both the mean and residual variance parts of the model are estimated together with their variance/covariance components. An important feature of …