http://espace.library.uq.edu.au/ The University of Queensland en Fez http://blogs.law.harvard.edu/tech/rss http://espace.library.uq.edu.au/view/UQ:146329 2008-06-06T00:00:00Z Jolly, L. http://espace.library.uq.edu.au/view/UQ:257466 2011-10-20T00:00:00Z Efatmaneshnik, Mahmoud og Reidsema, Carl Allen http://espace.library.uq.edu.au/view/UQ:12217 This paper provides a computational framework, based on Defeasible Logic, to capture some aspects of institutional agency. Our background is Kanger-Lindahl-P\"orn account of organised interaction, which describes this interaction within a multi-modal logical setting. This work focuses in particular on the notions of counts-as link and on those of attempt and of personal and direct action to realise states of affairs. We show how standard Defeasible Logic can be extended to represent these concepts: the resulting system preserves some basic properties commonly attributed to them. In addition, the framework enjoys nice computational properties, as it turns out that the extension of any theory can be computed in time linear to the size of the theory itself. 2007-02-02T00:00:00Z Governatori, Guido og Rotolo, Antonino http://espace.library.uq.edu.au/view/UQ:278783 2012-08-09T00:00:00Z Carter, J. P. og Wroth, C. P. og Booker, J. R. (John R.) http://espace.library.uq.edu.au/view/UQ:278768 2012-08-09T00:00:00Z Isaacs, L. T. (Lewis Thomas) http://espace.library.uq.edu.au/view/UQ:258557 2011-10-21T00:00:00Z Summerscales, John og Hall, Wayne og Virk, Amandeep Singh http://espace.library.uq.edu.au/view/UQ:196978 2010-02-26T00:00:00Z Lakner, R. og Nemeth, E. og Hangos, K. M. og Cameron, I. T. http://espace.library.uq.edu.au/view/UQ:259174 Final-year university engineering and journalism undergraduate students collaborate in a multimedia design and communication project to test the hypothesis that design and communication emphasis by engineering students can be enhanced by interdisciplinary collaboration with media-equipped journalism students. Research was conducted by environmental manipulation, observation, administration of a survey, and qualitative and quantitative analysis of media products. Participants reported increased media communication skills, an awareness of the necessity of communicating with other disciplines, and some change in their intended strategies for future projects. Evaluative instruments recorded a high level of student satisfaction with the collaboration. Evidence was obtained of a close relationship between engineering education and journalism education, leading to a level of interdisciplinarity among student participants. 2011-10-24T00:00:00Z Kavanagh, Lydia og Cokley, John http://espace.library.uq.edu.au/view/UQ:270946 Final-year university engineering and journalism undergraduate students collaborate in a multimedia design and communication project to test the hypothesis that design and communication emphasis by engineering students can be enhanced by interdisciplinary collaboration with media-equipped journalism students. Research was conducted by environmental manipulation, observation, administration of a survey, and qualitative and quantitative analysis of media products. Participants reported increased media communication skills, an awareness of the necessity of communicating with other disciplines, and some change in their intended strategies for future projects. Evaluative instruments recorded a high level of student satisfaction with the collaboration. Evidence was obtained of a close relationship between engineering education and journalism education, leading to a level of interdisciplinarity among student participants. 2012-03-21T00:00:00Z Kavanagh, Lydia og Cokley, John http://espace.library.uq.edu.au/view/UQ:256655 2011-10-18T00:00:00Z Hossain, M. Raquibul og Siddiquee, M. S. A. og Ahmad, S. I. http://espace.library.uq.edu.au/view/UQ:256693 Assessing and prioritising cost-effective strategies to mitigate the impact of traffic incidents on non-recurrent congestion on major roads are currently a major challenge for road network operations. There is a lack of relevant local research in this area. Several incident duration models developed from international research are not considered appropriate for Australian conditions due to different driver behaviour and traffic environment contexts. A comprehensive data mining research project was undertaken to analyse traffic incident data, obtained from the Queensland Department of Transport and Main Roads’ STREAMS Incident Management System (SIMS) for a one year period ending in November 2010. Various factors that contributed to frequency, type, characteristics, duration and location of traffic incidents were examined and the findings are discussed in this paper. Results indicate that breakdown, multiple vehicle crash and debris were the major sources of incidents. Although incident frequency dropped sharply on weekends, the average incident duration was similar or longer than those of weekdays. Also, rainfall increased the incident duration in all categories. Furthermore, a variety of probability distribution functions were employed in order to test the best model for each category of incident duration frequency distribution. Log-normal distribution was inferred to be appropriate for crash and stationary vehicle incidents and gamma distribution for hazard incidents. Future research directions have been identified, particularly the estimation of the impact (cost) of traffic incidents, to assist in prioritising investment. 2011-10-18T00:00:00Z Tavassoli Hojati, Ahmad og Charles, Phil og Ferreira, Luis og Kabit, Mohamad Raduan bin http://espace.library.uq.edu.au/view/UQ:278777 2012-08-09T00:00:00Z O'Connor, C. (Colin) http://espace.library.uq.edu.au/view/UQ:120926 Theoretical and experimental performance results for a new internal combustion engine configuration are presented in this paper. The engine is a piston ported, spark ignition petrol engine which consists of two opposed pistons in a single cylinder controlled by two synchronously timed crankshafts at opposite ends of the cylinder. It makes use of crank offset to create the required piston motion aimed at engine efficiency improvements through thermodynamic performance gains. In particular, the engine employs full expansion in which the power stroke displaces a larger volume than the compression stroke, thereby allowing the expanding gas to reach near atmospheric pressure before the exhaust port opens. This allows more work to be done by each thermodynamic cycle. It also features a greater rate of volume change after combustion than a convention 4-stroke engine for the same crank speed. This reduces the time that the temperature difference between the gas and the cylinder is high relative to a conventional engine which in turn, should reduce the heat lost from the combustion products. Thermodynamic and friction modelling of the engine indicated that efficiencies around 38% might be achieved. However, experiments with a prototype engine demonstrated that friction losses in the engine exceeded that predicted in the original modelling. 2007-12-19T00:00:00Z Malpress, R. og Buttsworth, D. R. http://espace.library.uq.edu.au/view/UQ:159546 The quality of field measurements in sewer systems relies on the spatial representativeness of the measurements. This study aims at field measurements of both velocity and total suspended solids (TSS) using a two dimensional sampler called Hydre. The device was implemented, tested and used in a sewer system for a range of hydraulic situations. This paper presents the principles of development and conception of the instrument. Analyses of the results demonstrate the ability of the device to provide robust TSS and velocity profiles in sewers for a range of flow conditions. L’évaluation des flux de polluants transitant dans les réseaux d’assainissement dépend notamment de la représentativité spatiale des mesures de vitesses et de concentrations en matières en suspension. Cette problématique a été étudiée expérimentalement par des mesures dans des réseaux urbains. Un échantillonneur bidimensionnel, appelé Hydre, a été développé et installé dans un collecteur. Il a permis d’étudier la répartition spatiale des vitesses et des concentrations pour une large gamme de contextes hydrauliques. Cet article présente la conception de cet échantillonneur. Les résultats sont présentés et discutés. Ils montrent la bonne homogénéité des concentrations dans la section mouillée. 2008-11-28T00:00:00Z Larrarte, Frédérique og Cottineau, Louis-Marie http://espace.library.uq.edu.au/view/UQ:278946 2012-08-16T00:00:00Z West, G. S http://espace.library.uq.edu.au/view/UQ:256664 It has been a long standing problem to solve the cyclic loading phenomena by a reasonably accurate cyclic model. Most of the existing cyclic models are unable to reproduce the memory effect i.e., material’s memory about its last load reversal point in the shear stress-strain plane, which produces a closed hysteretic loop. In this paper, a novel formulation of kinematic hardening rule is developed by extending the one dimensional Masing’s rule to general three dimensional stress-space. The cyclic behaviour is simulated by introducing a new framework in which the dimensionless kinematic hardening rate is varied according to the instantaneous stress value at that point along the stress path. When the direction of the loading is reversed, the initial rate of hardening is restored and the rate of variation of hardening is scaled according to extended Masing’s law. As a result, a closed hysteretic stress-strain loop is obtained due to cyclic loading. Also, a new hyperbolic growth function is used to simulate the rate of kinematic hardening. 2011-10-18T00:00:00Z Hossain, Md Raquibul og Siddiquee, Mohammed Saiful Alam og Ahmad, Syed Ishtiaq http://espace.library.uq.edu.au/view/UQ:278955 2012-08-16T00:00:00Z Sokal, Y. J. (Yehuda J.) http://espace.library.uq.edu.au/view/UQ:286243 This paper introduces an automatic feature extraction algorithm for bearing fault diagnosis using correlation filtering-based matching pursuit. This algorithm is described and investigated in theory and practice on both simulated and real bearing vibration signals. First, the vibration model for rolling bearing with fault is derived. Then, the numerical simulation signal being taken as an example, the principle of matching pursuit is mathematically explained and its drawbacks are analyzed. Afterward, to enhance the similarity of model related to the bearing faulty impulses, the model shape parameters are optimized using spectrum kurtosis and smoothing index. After that, the model with optimum shape and period parameters is taken as a template to approximate the impulses in faulty bearing signal. Finally, based on maximizing correlation principle, the optimized cycle parameter being as impuls e repetition period is matched up. The proposed method has been successfully applied in actual vibration signals of rolling element bearing with different faults. 2012-11-25T00:23:47Z Liu, Xiaofeng og Bo, Lin og He, Xingxi og Veidt, Martin http://espace.library.uq.edu.au/view/UQ:268990 Experimental methods, based on electromagnetic levitation, have been developed for preparation and investigation of copper-rich alloys, and for the determination of oxide-metal phase equilibria. These techniques involve high-temperature equilibration, rapid quenching and chemical analysis of the phases using electron probe X-ray microanalysis. The experiments can be carried out in the temperature range 1373-1873 K (= 1100 degrees C-1600 degrees C). A developed calibration method, using phase equilibria data in known oxide systems, was applied for pyrometric temperature measurements. Described methods of the application of the electro-magnetic levitations were used for in-situ formation of Cu-based alloys and for formation of Ca-ferrite slags equilibrated with metallic copper. 2012-03-06T00:00:00Z Ilyushechkin, Alexander Y. og Dolan, Michael og Dave, Narendra og Hayes, Peter C. og Jak, Eugene http://espace.library.uq.edu.au/view/UQ:278779 2012-08-09T00:00:00Z Beer, G. (Gernot) http://espace.library.uq.edu.au/view/UQ:144142 2008-06-05T00:00:00Z http://espace.library.uq.edu.au/view/UQ:245559 2011-08-14T00:00:00Z Gu, X.-F. og Zhang, W.-Z. og Qiu, D. http://espace.library.uq.edu.au/view/UQ:196544 We incorporated a new Riemannian fluid registration algorithm into a general MRI analysis method called tensor-based morphometry to map the heritability of brain morphology in MR images from 23 monozygotic and 23 dizygotic twin pairs. All 92 3D scans were fluidly registered to a common template. Voxelwise Jacobian determinants were computed from the deformation fields to assess local volumetric differences across subjects. Heritability maps were computed from the intraclass correlations and their significance was assessed using voxelwise permutation tests. Lobar volume heritability was also studied using the ACE genetic model. The performance of this Riemannian algorithm was compared to a more standard fluid registration algorithm: 3D maps from both registration techniques displayed similar heritability patterns throughout the brain. Power improvements were quantified by comparing the cumulative distribution functions of the p-values generated from both competing methods. The Riemannian algorithm outperformed the standard fluid registration. 2010-02-24T00:00:00Z Brun, Caroline og Leporé, Natasha og Pennec, Xavier og Chou, Yi-Yu og Lee, Agatha D. og Barysheva, Marina og De Zubicaray, Grieg og Meredith, Matthew og McMahon, Katie og Wright, Margaret J. og Toga, Arthur W. og Thompson, Paul M. http://espace.library.uq.edu.au/view/UQ:278975 2012-08-16T00:00:00Z Isaacs, L. T. (Lewis Thomas) og Carter, J. P. http://espace.library.uq.edu.au/view/UQ:183270 A comprehensive model is discussed for wet granulation based on a three-dimensional population balance, as an attempt to capture particle-level phenomena and their influence on the population-level behaviour. The three dimensions of population distribution are the particle size, binder content, and porosity of the granules. In formulating the population balance, these three particle traits are represented in terms of three equivalent traits, namely, the solid volume, liquid volume and gas volume of the granules. The model accounts for wetting, nucleation, aggregation and consolidation phenomena. Mechanistic kernels are derived for aggregation and nucleation, employing theories on these particle-level microscale phenomena that have already been validated in previous studies. The three-dimensional population balance is solved numerically using a finite volume-based decomposition algorithm also called the hierarchical two-tier solution strategy [Pinto, M.A., Immanuel, C.D., Doyle III, F.J., 2007. A feasible solution technique for higher-dimensional population balance models. Computers and Chemical Engineering, 31, 1242–1256]. 2009-09-03T00:00:00Z Poon, Jonathan M.-H. og Immanuel, Charles D. og Doyle, III, Francis J. og Litster, James D. http://espace.library.uq.edu.au/view/UQ:145867 2008-06-06T00:00:00Z Gourlay, M. R. http://espace.library.uq.edu.au/view/UQ:140746 This study examines the application of airborne electromagnetic (AEM) methodologies to bathymetry in shallow seawater and to map seafloor conductivity. Conductivity versus depth sections have been generated from a recent helicopter-borne DIGHEMV survey (operating vertical coaxial and horizontal coplanar transmitter-receiver coil geometries) of lower Port Jackson, Sydney Harbour. The sea depth ranges from about 1 to 30 m. Acoustic bathymetric soundings and marine seismic survey data provide the true seawater layer thickness and estimates of depth to bedrock respectively over most of the EM survey region. This complementary data can be used to evaluate the accuracy of airborne electromagnetic bathymetry. The efficacy of 1D conductivity inversion and rapid conductivity-depth imaging was investigated for shallow seawater overlaying marine sand sediments and sandstone. The inversion constructs layered conductivities which satisfy the AEM data to an accuracy consistent with the observational uncertainties. Inverted frequencies ranged from 328 to 55300 Hz. Resolution of the sea depth gave good agreement with known bathymetry (within about 10% or better) when inversion was unconstrained. Approximate conductivity-depth images obtained using program "EM Flow" gave similar agreement. Both inversion methods clearly identify the location and burial depth of higher resistivity regions associated with shallow marine sandstone bedrock. In addition to measuring water depths to about 30 m, this study has shown that the AEM DIGHEM technique provides a capability for remote sensing of seabed properties and offers the potential to detect areas of shallow bedrock and differentiate between consolidated and unconsolidated sediment in areas of seawater deeper than 25 m. 2008-06-10T00:00:00Z Vrbancich, J. og Fullagar, P. K. og Macnae, J. http://espace.library.uq.edu.au/view/UQ:279179 2012-08-20T10:53:45Z Gourlay, M. R. (Michael Richard) http://espace.library.uq.edu.au/view/UQ:160891 Inhibition of acetate addition on hydrogen production from sucrose-rich synthetic wastewater by mixed anaerobic culture was investigated in this study. Experimental results showed that the added acetate had a significant influence on both substrate degradation and hydrogen production during the fermentation process. The distribution of aqueous products was also influenced by the acetate addition. Modified logistic equations were able to simulate the acidogenesis process well, while a noncompetitive product inhibition model was successfully used to describe the inhibitory effects of acetate addition on both substrate degradation and hydrogen production. From kinetic analysis, the maximum specific rate View the MathML source, inhibition constant View the MathML source and the exponent of inhibition n=1.53 were estimated for sucrose degradation, whereas View the MathML source, View the MathML source and n=1.52 were calculated for hydrogen production. In addition, the CI,50 values of added acetate on the specific hydrogen production rate and hydrogen yield were 11.05 and 31.90 g/l, respectively. The fermentation patterns in the reactor were substantially changed because of the acetate addition, especially at higher dosages. 2009-01-15T00:00:00Z Wang, Yi og Zhao, Quan-Bao og Mu, Yang og Yu, Han-Qing og Harada, Hideki og Li, Yu-You http://espace.library.uq.edu.au/view/UQ:278960 2012-08-16T10:33:27Z West, G. S og Apelt, C. J. (Colin James) http://espace.library.uq.edu.au/view/UQ:278979 2012-08-16T11:37:57Z Kitipornchai, S. (Sritawat) og Dux, P. F. (Peter Francis) og Richter, Neville John http://espace.library.uq.edu.au/view/UQ:278980 2012-08-16T11:39:25Z Dux, P. F. (Peter Francis) og Kitipornchai, S. (Sritawat) http://espace.library.uq.edu.au/view/UQ:278778 2012-08-09T00:00:00Z Dux, P. F. (Peter Francis) og Kitipornchai, S. (Sritawat) http://espace.library.uq.edu.au/view/UQ:278018 2012-07-24T13:02:19Z Dux, P. F. (Peter Francis) og Kitipornchai, S. (Sritawat) http://espace.library.uq.edu.au/view/UQ:279191 2012-08-20T00:00:00Z Meek, J. L. (John L.) og Tranberg, W. F. C. http://espace.library.uq.edu.au/view/UQ:278988 2012-08-16T00:00:00Z Kitipornchai, S. (Sritawat) og Trahair, N. S. (Nicholas S.) http://espace.library.uq.edu.au/view/UQ:120832 After overhaul or repair, turbofan engines are tested to ensure reliability and thrust meet safe standards. For civil turbofans, these tests are conducted off the wing in indoor test cell facilities. The goal of test cell design is to develop a facility that generates repeatable airflow conditions. Current design and development techniques of jet engine test facilities utilise scaled physical models and 1-D numerical models. With recent development in inexpensive high speed computing recourses, computational fluid dynamics (CFD) has become a attractive method of designing and problem solving within such facilities. One of the principal issues in modelling test cell flow is the choice of turbulence model. The standard forms of the computationally efficient two-equation models are known to over-predict the length of wakes from bluff bodies in the flow e.g. the beams which support flow conditioning screens. For this application, the Reynolds Stress (RS) linear pressure strain model and LES based models are prohibitive in terms of computational expense. This work seeks a turbulence model suitable for simulations of test cell flow by tuning the constants of a two-equation RANS model. This is done to gain closer agreement to the downstream wake velocity field produced by a square cylinder disturbance to a uniformly flowing fluid. The k-w turbulence model with default parameters is selected as the most appropriate starting point for development. A parametric study suggests that a model with * and i both set at five times the default value as the best choice for test cell flow studies. This model adequately reproduced the velocity recovery after 4.5 cylinder diameters downstream. It did not reproduce the velocity structure in the recirculation zone immediately downstream of the cylinder. The details of the flow in this recirculation zone have minimal impact on the gross flow in the cell and are of secondary importance in this analysis. 2007-12-19T00:00:00Z Gilmore, Jordon og Jermy, Mark http://espace.library.uq.edu.au/view/UQ:83189 2007-08-15T00:00:00Z Couper, Malcolm J. og Rinderer, Barbara og Yao, Ji Yong http://espace.library.uq.edu.au/view/UQ:196890 Recently a considerable effort has been dedicated toward preparation of polymer/layer nanocomposites (polymer layered silicate (PLS) nanocomposites or polymer clay nanocomposites (PCNC)), which consist of a polymer matrix with a dispersed organic nanolayer. These composites have received considerable attention in fundamental research and industry. Interest in polyolefin nanocomposites has emerged due to their promise of improved performance in packaging and engineering applications. The most representative PE grades found in today’s market are LDPE, LLDPE and HDPE.1 Several workers have highlighted studies on the different structures of melt compounded clay and polyolefins, and the effect on the mechanical and thermal properties. These nanocomposites exhibit enhanced properties at very low filler content compared to conventional filled polymers, (usually inferior to 5 wt%) such as increased Young’s modulus, thermal stability, barrier properties, decreased gas/vapour permeability and good flame retardancy 2010-02-26T00:00:00Z Ghafor, Wael A. og Halley, Peter J. og Hill, David J. T. og Martin, Darren og Rasoul, Firas og Truss, Rowan R. og Whittaker, Andrew K. http://espace.library.uq.edu.au/view/UQ:285504 2012-11-15T15:19:55Z Shen, Qun og Li, Landong og He, Chi og Zhang, Xinyan og Hao, Zhengping og Xu, ZhiPing http://espace.library.uq.edu.au/view/UQ:278784 2012-08-09T00:00:00Z O'Connor, C. (Colin) http://espace.library.uq.edu.au/view/UQ:180778 2009-09-03T00:00:00Z Yuan, Tao og Cai, Rui og Wang, Ke og Ran, Ran og Liu, Shaomin og Shao, Zongping http://espace.library.uq.edu.au/view/UQ:180690 2009-09-03T00:00:00Z Barry, D. A. og Parlange, J.-Y. og Lockington, D. A. og Wissmeier, L. http://espace.library.uq.edu.au/view/UQ:258722 2011-10-21T00:00:00Z Hauck, C. og Scheuermann, A. http://espace.library.uq.edu.au/view/UQ:256669 2011-10-18T00:00:00Z Murshed, M. D. og Hossain, Md Raquibul og Siddiquee, M. S. A. http://espace.library.uq.edu.au/view/UQ:205935 2010-06-06T00:00:00Z He, Chi og Li, Jinjun og Li, Peng og Cheng, Jie og Hao, Zhengping og Xu, Zhi-Ping http://espace.library.uq.edu.au/view/UQ:279197 2012-08-20T00:00:00Z Carter, J. P. og Booker, J. R. (John R.) http://espace.library.uq.edu.au/view/UQ:278997 2012-08-16T00:00:00Z Behan, John Ernest http://espace.library.uq.edu.au/view/UQ:278952 2012-08-16T00:00:00Z Koretsky, A. V og Pritchard, R. W http://espace.library.uq.edu.au/view/UQ:145844 2008-06-06T00:00:00Z Grigg, L. J.