Open Access. Powered by Scholars. Published by Universities.®

Science and Technology Studies Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 15 of 15

Full-Text Articles in Science and Technology Studies

Bayesian Learning And Predictability In A Stochastic Nonlinear Dynamical Model, John Parslow, Noel Cressie, Edward P. Campbell, Emlyn Jones, Lawrence Murray Feb 2016

Bayesian Learning And Predictability In A Stochastic Nonlinear Dynamical Model, John Parslow, Noel Cressie, Edward P. Campbell, Emlyn Jones, Lawrence Murray

Professor Noel Cressie

Bayesian inference methods are applied within a Bayesian hierarchical modelling framework to the problems of joint state and parameter estimation, and of state forecasting. We explore and demonstrate the ideas in the context of a simple nonlinear marine biogeochemical model. A novel approach is proposed to the formulation of the stochastic process model, in which ecophysiological properties of plankton communities are represented by autoregressive stochastic processes. This approach captures the effects of changes in plankton communities over time, and it allows the incorporation of literature metadata on individual species into prior distributions for process model parameters. The approach is applied …


A Lifetime Individual Sampling Model (Ism) For Heroin Use And Treatment Evaluation In Australia, Nagesh Shukla, Van Hoang, Marian Shahanan, Alison Ritter, Vu Lam Cao, Pascal Perez Sep 2015

A Lifetime Individual Sampling Model (Ism) For Heroin Use And Treatment Evaluation In Australia, Nagesh Shukla, Van Hoang, Marian Shahanan, Alison Ritter, Vu Lam Cao, Pascal Perez

Nagesh Shukla

Illicit drug use has created an enormous burden at societal, family and personal levels. Every year a significant amount of resources is allocated for treatment and the consequences of illicit drug use in Australia and around the world. Heroin is one of the major forms of illicit drugs that are used illegally. Several independent heroin treatment strategies or interventions exist and state-of-the-art research demonstrates their efficacy and relative cost-effectiveness. However, assessing total potential gains and burden from providing all treatment interventions or varying the mix of heroin treatments has never been attempted. Furthermore, the need to include multiple treatments, multiple …


A Novel Integrated Model To Measure Supplier Performance Considering Qualitative And Quantitative Criteria Used In The Supplier Selection Process, Alptekin Ulutas, Senevi Kiridena, Peter Gibson, Nagesh Shukla Apr 2015

A Novel Integrated Model To Measure Supplier Performance Considering Qualitative And Quantitative Criteria Used In The Supplier Selection Process, Alptekin Ulutas, Senevi Kiridena, Peter Gibson, Nagesh Shukla

Nagesh Shukla

Supplier evaluation has become a significant topic over the past few decades, as companies have become more outsourced oriented. However, previous research on this topic has not paid adequate attention to the limitations associated with the availability of accurate and reliable data relating to the performance of potential suppliers. In an attempt to address this issue, this paper proposes a novel supplier evaluation model that can handle imprecise quantitative and qualitative data. Additionally, Decision Maker's judgement regarding both qualitative and quantitative criteria are incorporated into this model so that a more comprehensive and realistic assessment of supplier performance can be …


Conceptual Model Describing Smear Zone Caused By Mandrel Action, Cholachat Rujikiatkamjorn, Made Ardana, Buddhima Indraratna, S Leroueil Mar 2014

Conceptual Model Describing Smear Zone Caused By Mandrel Action, Cholachat Rujikiatkamjorn, Made Ardana, Buddhima Indraratna, S Leroueil

Cholachat Rujikiatkamjorn

In this study the characteristics and extent of the smear zone are investigated using a large, undisturbed sample. The aim of using such a sample is to capture the realistic characteristics of the smear zone in relation to the in situ soil structure during the installation of prefabricated vertical drains (PVDs) using a mandrel. The extent of the smear zone for Bulli clay (New South Wales, Australia) is determined on the basis of normalised permeability (k(h)/k(hu)) and the reduction in the water content upon consolidation. The permeability and compressibility of the soil are investigated to determine the extent to which …


Conceptual Model Describing Smear Zone Caused By Mandrel Action, Cholachat Rujikiatkamjorn, Made Ardana, Buddhima Indraratna, S Leroueil Mar 2014

Conceptual Model Describing Smear Zone Caused By Mandrel Action, Cholachat Rujikiatkamjorn, Made Ardana, Buddhima Indraratna, S Leroueil

Buddhima Indraratna

In this study the characteristics and extent of the smear zone are investigated using a large, undisturbed sample. The aim of using such a sample is to capture the realistic characteristics of the smear zone in relation to the in situ soil structure during the installation of prefabricated vertical drains (PVDs) using a mandrel. The extent of the smear zone for Bulli clay (New South Wales, Australia) is determined on the basis of normalised permeability (k(h)/k(hu)) and the reduction in the water content upon consolidation. The permeability and compressibility of the soil are investigated to determine the extent to which …


Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Buddhima Indraratna

A modified 150 mm Rowe cell equipped with pore water pressure measurement was used to capture the flow relationship during vacuum-assisted radial consolidation. Based on the measured data, a radial consolidation model incorporating the effects of vacuum preloading is proposed, based on a non-linear relationship between the flow velocity and hydraulic gradient. The predictions of the proposed consolidation model are then compared with the predictions based on Hansbo’s Darcian and non- Darcian models. The agreement between the proposed model and the measured data is shown, and the advantages of the proposed model compared with the existing models are discussed. An …


Leakage Resilient Authenticated Key Exchange Secure In The Auxiliary Input Model, Guomin Yang, Yi Mu, Willy Susilo, Duncan S. Wong Mar 2014

Leakage Resilient Authenticated Key Exchange Secure In The Auxiliary Input Model, Guomin Yang, Yi Mu, Willy Susilo, Duncan S. Wong

Professor Willy Susilo

Authenticated key exchange (AKE) protocols allow two parties communicating over an insecure network to establish a common secret key. They are among the most widely used cryptographic protocols in practice. In order to resist key-leakage attacks, several leakage resilient AKE protocols have been proposed recently in the bounded leakage model. In this paper, we initiate the study on leakage resilient AKE in the auxiliary input model. A promising way to construct such a protocol is to use a digital signature scheme that is entropically-unforgeable under chosen message and auxiliary input attacks. However, to date we are not aware of any …


Similarity-Based Search For Model Checking: A Pilot Study With Java Pathfinder, Elmin Ibrahimov, Jixing Wang, Zhiquan Zhou Jan 2014

Similarity-Based Search For Model Checking: A Pilot Study With Java Pathfinder, Elmin Ibrahimov, Jixing Wang, Zhiquan Zhou

Dr Zhiquan Zhou

When a model checker cannot explore the entire state space because of limited resources, model checking becomes a kind of testing with an attempt to find a failure (violation of properties) quickly. We consider two state sequences in model checking: (i) the sequence in which new states are generated, and (ii) the sequence in which the states generated in sequence (i) are checked for property violation. We observe that neighboring states in sequence (i) often have similarities in certain ways. Based on this observation we propose a search strategy, which generates sequence (ii) in such a way that similar states …


An Adaptive Bilateral Negotiation Model Based On Bayesian Learning, Chao Yu, Fenghui Ren, Minjie Zhang Oct 2013

An Adaptive Bilateral Negotiation Model Based On Bayesian Learning, Chao Yu, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

Endowing the negotiation agent with a learning ability such that a more beneficial agreement might be obtained is increasingly gaining attention in agent negotiation research community. In this paper, we propose a novel bilateral negotiation model based on Bayesian learning to enable self-interested agents to adapt negotiation strategies dynamically during the negotiation process. Specifically, we assume that two agents negotiate over a single issue based on time-dependent tactic. The learning agent has a belief about the probability distribution of its opponent's negotiation parameters (i.e., the deadline and reservation offer). By observing opponent's historical offers and comparing them with the fitted …


An Investigation On The Impacts Of Density Currents On The Sedimentation In Dam Reservoirs Using Tcm Model; Case Study: Maroon Dam, Farhad Raof, Mohammad Naghshine, Ali Khoshrftar Sep 2013

An Investigation On The Impacts Of Density Currents On The Sedimentation In Dam Reservoirs Using Tcm Model; Case Study: Maroon Dam, Farhad Raof, Mohammad Naghshine, Ali Khoshrftar

Farhad Fakheri Raof

Sedimentation in dams' reservoirs is one of the most pressing concerns facing dams today. Maroon reservoir dam, located in Khuzestan Province, is one of the most important dams in this region. Since it is a new constructed dam, numerical simulation of sedimentation trend in its reservoirs could significantly help on a better utilization. To this end, TCM model which is capable to simulate density currents was used. The obtained results show that the dam loses about 91 million m3 of its reservoirs during a 50-year exploitation period.


Studying The Impact Of The Corner Propagation Model On Vanet Routing In Urban Environments, Abhinay Mukunthan, Craig Cooper, Farzad Safaei, D. Franklin, Mehran Abolhasan Jun 2013

Studying The Impact Of The Corner Propagation Model On Vanet Routing In Urban Environments, Abhinay Mukunthan, Craig Cooper, Farzad Safaei, D. Franklin, Mehran Abolhasan

Professor Farzad Safaei

Accurate modelling of the radio channel is often the most difficult aspect of a Vehicular Ad Hoc Network (VANET) simulation due to the large variability present in vehicular terrain. CORNER is a propagation model that calculates path-loss in an urban terrain with a large concentration of buildings, based on the position of the transmitter and receiver on a street map. This paper proposes additions to the CORNER propagation model to take selective multi-path fading into account and investigates the performance of the GPSR routing protocol under the CORNER propagation model in a realistic city environment.


Ignoring A Level In A Multilevel Model: Evidence From Uk Census Data, Mark Tramner, David Steel Jun 2013

Ignoring A Level In A Multilevel Model: Evidence From Uk Census Data, Mark Tramner, David Steel

Professor David Steel

Because of the inherent multilevel nature of census data, it is often appropriate to use multilevel models to investigate relationships between census variables. For a local population, the data available from the census allow a three-level nested model to be assumed, with an individual level (level 1), an enumeration district (ED) level (level 2), and a ward level (level 3). The consequences of ignoring one of the three levels in this model are assessed here theoretically. Empirical results, based on 1991 UK Census data, are also provided, comparing the variance components estimated from the three-level model with analyses based on …


An Introduction To Model-Based Survey Sampling With Applications, Raymond Chambers, Robert Clark May 2013

An Introduction To Model-Based Survey Sampling With Applications, Raymond Chambers, Robert Clark

Robert Clark

No abstract provided.


Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera Feb 2013

Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera

Dr Philip Ciufo

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …


Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang Feb 2013

Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang

Professor Weihua Li

In this paper, an integrated vehicle seat and sus pension control strategy for a quarter car with driver model is proposed to improve suspension performance on driver ride comfort. An integrated seat and suspension model that includes a quarter-car suspension, a seat suspension, and a 4-degree-of freedom (DOM) driver body model is presented first. This in1 tegrated model provides a platform to evaluate ride comfort 1performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car suspensions. Based on the integrated model, an H∞ state feedback controller is designed …