ORCID Profile
0000-0002-5351-3104
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Stochastic Analysis And Modelling | Statistics | Communications Technologies | Stochastic Analysis and Modelling | Operations Research | Computer Communications Networks | Wildlife and Habitat Management | Mathematical Sciences Not Elsewhere Classified | Broadband Network Technology | Mathematical Physics | Optimisation | Conservation and Biodiversity | Applied Statistics |
Mathematical sciences | Telecommunications | Expanding Knowledge in the Mathematical Sciences | Education and training not elsewhere classified | Living resources (flora and fauna) | Ecosystem Assessment and Management at Regional or Larger Scales | Land and water management | Other | Flora, Fauna and Biodiversity at Regional or Larger Scales
Publisher: Elsevier BV
Date: 02-2017
Publisher: Informa UK Limited
Date: 1998
Publisher: Elsevier BV
Date: 05-2000
Publisher: Cambridge University Press (CUP)
Date: 07-1995
DOI: 10.1017/S0269964800003909
Abstract: In this paper we present a unified approach to the optimal dimensioning and tariffing of loss networks. In our formulation the optimum is chosen to maximize the profit for the company operating the loss network. We assume that the operating company has the flexibility to determine tariffs and grade of service — although both of these can possibly be subject to regulatory constraints. The fact that the tariffing may affect demand and, hence, the dimensioning makes it essential that the operating company include the tariff/demand trade-off in determining the optimal way to dimension the loss network. A consequence of our formulation is that the optimal tariff structure has a particularly simple form, with the optimal tariff on a particular route separating into a term related to the tariff/demand trade-off on that route and a term that reflects the cost of the circuits used by the route.
Publisher: Cambridge University Press (CUP)
Date: 13-11-2009
DOI: 10.1017/S0269964809000102
Abstract: We consider a Markovian stochastic fluid flow model in which the fluid level has a lower bound zero and a positive upper bound. The behavior of the process at the boundaries is modeled by parameters that are different than those in the interior and allow for modeling a range of desired behaviors at the boundaries. We illustrate this with ex les. We establish formulas for several time-dependent performance measures of significance to a number of applied probability models. These results are achieved with techniques applied within the fluid flow model directly. This leads to useful physical interpretations, which are presented.
Publisher: IEEE
Date: 11-2007
Publisher: Springer Science and Business Media LLC
Date: 02-2005
Publisher: Wiley
Date: 2018
DOI: 10.14814/PHY2.13551
Publisher: Springer Science and Business Media LLC
Date: 27-08-2021
DOI: 10.1007/S12020-021-02851-6
Abstract: Recently published papers have demonstrated that particularly in untreated in iduals, clinical parameters more often associate with thyroid hormone, particularly free thyroxine (FT4), levels than with thyrotropin (TSH) levels. Clinical and research assessments of the thyroid state of peripheral tissues would therefore be more precise if they were based on FT4 levels rather than on TSH levels. In this paper we describe implications of, and opportunities provided by, this discovery. The FT4 level may be the best single test of thyroid function. The addition of free triiodothyronine (FT3) and TSH levels would further enhance test sensitivity and distinguish primary from secondary thyroid dysfunction respectively. There are opportunities to reconsider testing algorithms. Additional potential thyroidology research subjects include the peripheral differences between circulating FT4 and FT3 action, and outcomes in patients on thyroid replacement therapy in terms of thyroid hormone levels. Previously performed negative studies of therapy for subclinical thyroid dysfunction could be repeated using thyroid hormone levels rather than TSH levels for subject selection and the monitoring of treatment. Studies of outcomes in older in iduals with treatment of high normal FT4 levels, and pregnant women with borderline high or low FT4 levels would appear to be the most likely to show positive results. There are fresh indications to critically re-analyse the physiological rationale for the current preference for TSH levels in the assessment of the thyroid state of the peripheral tissues. There may be opportunities to apply these research principles to analogous parameters in other endocrine systems.
Publisher: Elsevier BV
Date: 05-2014
Publisher: ACM
Date: 09-11-2009
Publisher: Informa UK Limited
Date: 02-2013
Publisher: Elsevier BV
Date: 10-2018
Publisher: IEEE
Date: 06-2007
DOI: 10.1109/ICC.2007.586
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.JAMDA.2010.05.008
Abstract: With aging there is an increase in frailty and chronic disease leading to a potential increase in medication use. Most clinical trials have excluded old, frail in iduals and have failed to take into account the effects of outcome interaction. In this article we provide a mathematical model demonstrating that comorbidities, including old age, interact with therapies, reducing their effectiveness. These findings question the validity of single disease guidelines in old persons or in persons with multiple chronic diseases.
Publisher: Springer Science and Business Media LLC
Date: 08-1994
DOI: 10.1007/BF02024521
Publisher: IEEE
Date: 11-2007
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.JTBI.2016.01.012
Abstract: Epidemic fade-out refers to infection elimination in the trough between the first and second waves of an outbreak. The number of infectious in iduals drops to a relatively low level between these waves of infection, and if elimination does not occur at this stage, then the disease is likely to become endemic. For this reason, it appears to be an ideal target for control efforts. Despite this obvious public health importance, the probability of epidemic fade-out is not well understood. Here we present new algorithms for approximating the probability of epidemic fade-out for the Markovian SIR model with demography. These algorithms are more accurate than previously published formulae, and one of them scales well to large population sizes. This method allows us to investigate the probability of epidemic fade-out as a function of the effective transmission rate, recovery rate, population turnover rate, and population size. We identify an interesting feature: the probability of epidemic fade-out is very often greatest when the basic reproduction number, R0, is approximately 2 (restricting consideration to cases where a major outbreak is possible, i.e., R0>1). The public health implication is that there may be instances where a non-lethal infection should be allowed to spread, or antiviral usage should be moderated, to maximise the chance of the infection being eliminated before it becomes endemic.
Publisher: IEEE
Date: 11-2007
Publisher: IEEE
Date: 10-2008
Publisher: Springer Science and Business Media LLC
Date: 10-05-2008
Publisher: figshare
Date: 2021
Publisher: Cambridge University Press (CUP)
Date: 12-1998
Abstract: Olivier and Walrand (1994) claimed that the departure process of an MMPP/M/1 queue is not an MAP unless the queue is a stationary M/M/1 queue. They also conjectured that the departure process of an MAP/PH/1 queue is not an MAP unless the queue is a stationary M/M/1 queue. We show that their proof of the first result has an algebraic error, which leaves open the above question of whether the departure process of an MMPP/M/1 can be an MAP.
Publisher: Elsevier BV
Date: 06-2010
Publisher: Springer Science and Business Media LLC
Date: 04-2006
Publisher: IEEE
Date: 12-2008
Publisher: Informa UK Limited
Date: 09-02-2005
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 15-11-2012
DOI: 10.1007/S11538-011-9700-2
Abstract: In this paper, we present a model of cell cycle progression and apply it to cells of the MCF-7 breast cancer cell line. We consider cells existing in the three typical cell cycle phases determined using flow cytometry: the G1, S, and G2/M phases. We further break each phase up into model phases in order to capture certain features such as cells remaining in phases for a minimum amount of time. The model is also able to capture the environmentally responsive part of the G1 phase, allowing for quantification of the number of environmentally responsive cells at each point in time. The model parameters are carefully chosen using data from various sources in the biological literature. The model is then validated against a variety of experiments, and the excellent fit with experimental results allows for insight into the mechanisms that influence observed biological phenomena. In particular, the model is used to question the common assumption that a 'slow cycling population' is necessary to explain some results. Finally, an extension is proposed, where cell death is included in order to accurately model the effects of tamoxifen, a common first line anticancer drug in breast cancer patients. We conclude that the model has strong potential to be used as an aid in future experiments to gain further insight into cell cycle progression and cell death.
Publisher: IEEE
Date: 2003
Publisher: Elsevier BV
Date: 05-2011
Publisher: Springer Berlin Heidelberg
Date: 2009
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 05-2000
Publisher: Informa UK Limited
Date: 08-2008
Publisher: WORLD SCIENTIFIC
Date: 06-2002
Publisher: Springer Science and Business Media LLC
Date: 17-09-2022
DOI: 10.1007/S12020-022-03184-8
Abstract: The sensitivities of the pituitary to thyroxine feedback, and the thyroid to thyrotropin stimulation determine the free thyroxine /thyrotropin feedback loop and can be described mathematically by two curves. It is not well understood how the two curves combine in a healthy population with normal thyroid function to express the in idual balance points that are observed. This study was directed at this issue testing the possibilities of random combination and directed linkage between the two curves. We reverse-engineered two sets of population data, on the assumption of independent combinations of thyroid and pituitary sensitivities, to obtain estimates of the curve describing thyroid sensitivity. Sensitivity studies were performed. No analysis resulted in a physiologically feasible estimate of the curve describing thyroid sensitivity. There was evidence of linkage of the two curves in terms of their combination throughout the normal range. Thyroid response curves reflecting a low free thyroxine response to thyrotropin tended to be combined in in iduals with thyrotropin curves reflecting a high thyrotropin response to free thyroxine, and vice versa. Thyroid and pituitary sensitivities are linked, being combined in in iduals in a non-random directed pattern. Direct mutual interaction may contribute to this linkage. This linkage precludes the derivation of the curves describing these sensitivities from population data of the free thyroxine and thyrotropin relationship and complicates their derivation by physiological experimentation. This linkage and probable interaction may also bestow evolutionary advantage by minimising inter-in idual variation in free thyroxine levels and by augmenting homeostasis.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Cambridge University Press (CUP)
Date: 03-1995
DOI: 10.2307/1428107
Abstract: In this paper we consider the analysis of call blocking at a single resource with differing capacity requirements as well as differing arrival rates and holding times. We include in our analysis trunk reservation parameters which provide an important mechanism for tuning the relative call blockings to desired levels. We base our work on an asymptotic regime where the resource is in heavy traffic. We further derive, from our asymptotic analysis. methods for the analysis of finite systems. Empirical results suggest that these methods perform well for a wide class of ex les.
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: Research Square Platform LLC
Date: 24-08-2021
DOI: 10.21203/RS.3.RS-800178/V1
Abstract: The evolutionarily recent dispersal of Anatomically Modern Humans (AMH) out of Africa and across Eurasia provides an opportunity to study rapid genetic adaptation to multiple new environments. Genomic analyses of modern human populations have detected limited signals of strong selection such as hard sweeps, but genetic admixture between populations is capable of obscuring these patterns and is well known in recent human history, such as during the Bronze Age4. Here we show that ancient human genomic datasets contain multiple genetic signatures of strong selection including 57 hard sweeps, many with strong associations with cold adaptation. Similar genetic signatures of adaptation are also observed in adaptively-introgressed archaic hominin loci, as well as modern Arctic human groups. Consistent targets include the regulation of fat storage, skin physiology, cilia function and neural development with multiple associations to modern western diseases. The spatiotemporal patterns of the hard sweeps allow reconstruction of early AMH population dispersals, and reveal a prolonged period of genetic adaptation (~80-50,000 years) following their initial out of Africa movement, before a rapid spread across Eurasia reaching as far as Australia.
Publisher: Informa UK Limited
Date: 04-08-2010
Publisher: Elsevier BV
Date: 09-2005
Publisher: Elsevier BV
Date: 10-2005
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.MBS.2018.07.007
Abstract: Dose-response studies are used throughout pharmacology, toxicology and in clinical research to determine safe, effective, or hazardous doses of a substance. When involving animals, the subjects are often housed in groups this is in fact mandatory in many countries for social animals, on ethical grounds. An issue that may consequently arise is that of unregulated between-subject dosing (transmission), where a subject may transmit the substance to another subject. Transmission will obviously impact the assessment of the dose-response relationship, and will lead to biases if not properly modelled. Here we present a method for determining the optimal design - pertaining to the size of groups, the doses, and the killing times - for such group dose-response experiments, in a Bayesian framework. Our results are of importance to minimising the number of animals required in order to accurately determine dose-response relationships. Furthermore, we additionally consider scenarios in which the estimation of the amount of transmission is also of interest. A particular motivating ex le is that of C ylobacter jejuni in chickens. Code is provided so that practitioners may determine the optimal design for their own studies.
Publisher: Walter de Gruyter GmbH
Date: 12-2022
Abstract: Statistical analysis in competitive sport is an important tool for developing strategy and seeking competitive advantages. However, for complex team sports such as Australian Rules Football, major limitations occur when using possession event data for game analysis. First, focusing on counting possession events does not capture the impact of off-the-ball actions such as ground positioning of other players. Second, it is difficult to determine the extent that an event is due to either team’s relative proficiency or skill. Third, there is limited possession event data available from each match and modelling efforts often have low statistical power. Here we reinterpret event data into positional systems and utilise pairwise performance metrics to understand the relative team proficiency in each of these states. These metrics can then be used to construct transition probabilities between states for future games, and ultimately, absorbing probabilities of goal states. Our approach effectively predicts match outcomes using team ratings for forward, midfield and defensive systems and is sufficiently interpretable to support strategic decision-making by coaching departments in the Australian Football League (AFL).
Publisher: Elsevier BV
Date: 03-2020
Publisher: Association for Computing Machinery (ACM)
Date: 09-03-2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2010
Publisher: IEEE
Date: 10-2008
Publisher: Thomas Telford Ltd.
Date: 12-2064
DOI: 10.1680/WAMA.900053
Abstract: The management of three connected reservoirs for the capture, storage and supply of urban stormwater is modelled using a pump-to-fill policy that minimises the volume of water lost to overflow. A discrete state Markov model is used with constant daily demand from the supply reservoir and stochastic inflow to the capture reservoir. The pump-to-fill policy is completely deterministic and depends only on the current volume in the supply, storage and capture reservoirs. By judicious ordering of the states the very large transition matrix is shown to possess a nested block upper Hessenberg structure. Standard censoring methods reduce the analysis of the system to a characteristic sequence of full-to-full transitions for the supply reservoir. The nested block structure of the original transition matrix is captured using special recursive algebraic procedures that enable a further reduction to a sequence of simultaneous full-to-full transitions for the supply and storage reservoirs. Capabilities of the model are demonstrated through application to a hypothetical three-reservoir network for the capture and supply of water. The methods proposed in this paper could be used to calculate the steady-state probabilities for three-reservoir storage systems and could assist projections for future water supply capabilities. This paper also provides insight into how the analysis could be extended to systems of more than three reservoirs.
Publisher: ACM
Date: 07-06-2011
Publisher: Wiley
Date: 07-05-2014
DOI: 10.1111/FOG.12069
Publisher: Springer Science and Business Media LLC
Date: 06-12-2008
Publisher: Springer Science and Business Media LLC
Date: 11-12-2007
Publisher: Proceedings of the National Academy of Sciences
Date: 23-05-2023
Abstract: The evolutionarily recent dispersal of anatomically modern humans (AMH) out of Africa (OoA) and across Eurasia provides a unique opportunity to examine the impacts of genetic selection as humans adapted to multiple new environments. Analysis of ancient Eurasian genomic datasets (~1,000 to 45,000 y old) reveals signatures of strong selection, including at least 57 hard sweeps after the initial AMH movement OoA, which have been obscured in modern populations by extensive admixture during the Holocene. The spatiotemporal patterns of these hard sweeps provide a means to reconstruct early AMH population dispersals OoA. We identify a previously unsuspected extended period of genetic adaptation lasting ~30,000 y, potentially in the Arabian Peninsula area, prior to a major Neandertal genetic introgression and subsequent rapid dispersal across Eurasia as far as Australia. Consistent functional targets of selection initiated during this period, which we term the Arabian Standstill, include loci involved in the regulation of fat storage, neural development, skin physiology, and cilia function. Similar adaptive signatures are also evident in introgressed archaic hominin loci and modern Arctic human groups, and we suggest that this signal represents selection for cold adaptation. Surprisingly, many of the candidate selected loci across these groups appear to directly interact and coordinately regulate biological processes, with a number associated with major modern diseases including the ciliopathies, metabolic syndrome, and neurodegenerative disorders. This expands the potential for ancestral human adaptation to directly impact modern diseases, providing a platform for evolutionary medicine.
Publisher: Elsevier BV
Date: 09-2012
Publisher: No publisher found
Date: 2003
Publisher: Elsevier BV
Date: 05-2000
Publisher: Cambridge University Press (CUP)
Date: 12-2010
Abstract: The numerical analysis of quasi-birth-and-death processes rests on the resolution of a matrix-quadratic equation for which efficient algorithms are known when the matrices have finite order, that is, when the number of phases is finite. In this paper we consider the case of infinitely many phases from the point of view of theoretical convergence of truncation and augmentation schemes, and we develop four different methods. Two methods rely on forced transitions to the boundary. In one of these methods, the transitions occur as a result of the truncation itself, while in the other method, they are artificially introduced so that the augmentation may be chosen to be as natural as possible. Two other methods rely on forced transitions within the same level. We conclude with a brief numerical illustration.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.MBS.2014.04.004
Abstract: Cellular automata are discrete agent-based models, generally used in cell-based applications. There is much interest in obtaining continuum models that describe the mean behaviour of the agents in these models. Previously, continuum models have been derived for agents undergoing motility and proliferation processes, however, these models only hold under restricted conditions. In order to narrow down the reason for these restrictions, we explore three possible sources of error in deriving the model. These sources are the choice of limiting arguments, the use of a discrete-time model as opposed to a continuous-time model and the assumption of independence between the state of sites. We present a rigorous analysis in order to gain a greater understanding of the significance of these three issues. By finding a limiting regime that accurately approximates the conservation equation for the cellular automata, we are able to conclude that the inaccuracy between our approximation and the cellular automata is completely based on the assumption of independence.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2008
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 2007
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 2013
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 2013
Funder: Australian Research Council
View Funded ActivityStart Date: 2002
End Date: 2004
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2003
Funder: Australian Research Council
View Funded ActivityStart Date: 2014
End Date: 2020
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 12-2015
Amount: $255,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 12-2003
Amount: $20,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 12-2010
Amount: $198,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2002
End Date: 12-2005
Amount: $183,611.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 12-2013
Amount: $645,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 12-2008
Amount: $388,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2004
End Date: 03-2008
Amount: $490,102.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 06-2015
Amount: $600,000.00
Funder: Australian Research Council
View Funded Activity