http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10929 Structural reliability analyses are commonly applied to estimation of probabilities of structural damage to static and dynamic loads such as earthquake, wind and wave loads. Although blast loadings acting on structures from accidental explosions or hostile bombings are very difficult to be accurately predicted owing to many uncertain parameters that influence explosion shock wave propagation and shock wave interaction with structures, reliability analyses of structural failure to blast loadings with consideration of uncertainties in blast loading and structural parameters are very limited. Instead, a large safety factor is usually used to account for uncertain variations in blast loading and structural parameters in blast-resistant design and analysis. This may lead to an inaccurate design of structures to resist blast loads, and an inaccurate assessment of structure performance in a given explosion scenario. In this study, reliability analyses of three example RC columns to randomly varying blast loads are carried out. The column dimensions, reinforcement ratios and material strengths are assumed to be normally distributed with the respective design parameters as the mean values. The mean value and standard deviation of the peak reflected pressure and duration of the blast load at various scaled distances are derived from available empirical formulae, and are used in this study to model the blast pressure variations. Failure probabilities of the example RC columns subjected to blast loads of different scaled distances are estimated. Numerical results are compared with those obtained with the deterministic blast loading or deterministic column property assumptions. The importance of considering the random variations of structural properties and blast loadings in assessing the blast load effects on RC columns is discussed. 2012-06-19T01:15:10.479Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10648 Chironex fleckeri (box jellyfish) are found in the northern tropical waters of Australia. Although C. fleckeri have a wide geographical distribution and are able to swim large distances, adults tend to stay in small restricted areas. Clinical data shows that deaths from envenoming have not been recorded in Western Australia, yet numerous fatalities have occurred in Northern Territory and Queensland waters. One explanation for this discrepancy is a geographical variation in venom composition. This study examined the pharmacological and biochemical profiles of C. fleckeri venom from different geographical locations and seasons. Venoms were screened for cytotoxicity using a rat aortic smooth muscle cell line (A7r5). While all venoms caused concentration-dependent cytotoxicity, differences were seen in the potency of venoms from Mission Beach and Weipa, when collected in different seasons, as indicated by IC50 values. Similarly venoms collected within the same season, from different locations around Australia, displayed marked differences in venom composition as shown by size exclusion HPLC and SDS-PAGE profiles which indicated the absence or reduced quantity of ‘peaks’ in some venoms. Based on IC50 data obtained from the cell assay, the effects of the most potent (i.e. from Weipa in 2006) and the least potent (i.e. from Broome in 2007) venoms were examined in anesthetised rats. Both venoms at 10 μg/kg (i.v.) caused a transient hypertensive phase followed by cardiovascular collapse. However, at 4 μg/kg (i.v.) venom from Weipa 2006 caused a transient hypertensive phase followed by a transient decrease in MAP while venom from Broome 2007 only caused a small transient increase in MAP. This study demonstrates that there is considerable geographical variation in the composition of C. fleckeri venoms which is most distinct between specimens from western and eastern Australia and may explain the geographical variation in reported deaths. 2012-04-16T01:37:59.332Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8770 Feature models are used in member product configuration in software product lines. A valid product configuration must satisfy two kinds of constraints, multiplicity of each variation point and dependencies among the variants in a product line. The combined impact of the two kinds of constrains on product configuration should be well understood. In this paper we propose a measurement, called VariationRank, that combines the two kinds of constraints to assess the complexity of variation points in software product lines. Based on the measurement we can identify those variation points with the highest impact on product configurations in a product line. This information could be used as guidance in product configuration as well as for feature model optimization in software product lines. A case study is presented and discussed in this paper as well. 2012-03-07T23:01:37.313Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2478 Research Doctorate - Doctor of Philosophy (PhD) 2011-12-13T01:00:19.575Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6281 Research Doctorate - Doctor of Philosophy (PhD) 2011-12-07T23:50:04.355Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9006 This paper provides an in-depth study of the linkage between firm-specific variation in returns and fundamentals in Korea. While international studies of the emerging Asian market shows firm stock prices variation is related to their fundamentals there is a common problem of inaccuracy and lack of sufficient number of samples. We try to overcome the insufficiency of the spans of time-series data and consequent loss of statistical testing power by using firm-level micro panel data from Korean stock market. Using detailed accounting data, we test for the Fama-French 3 factor models, and see if the increasing foreign investor participation in the Korean market has effect upon the relation between stock prices and fundamentals. The results show positive correlations and significant firm-specific information incorporated in the stock price volatility. Also, firms with higher foreigner shareholder ratio, used to proxy for stock monitoring and corporate governance, seemed to show higher correlation between cash flow shocks and stock price returns volatility. 2011-09-19T05:00:04.476Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8355 The only species of the genus Triops in Australia, T. australiensis, is found to reproduce by gonochorism. Morphological and reproductive data and molecular analyses of fragments of mitochondrial genes 12S rRNA (12S) and cytochrome oxidase I (COI) indicate that a Triops population from the middle Paroo in north-western New South Wales is composed of two different entities, Triops cf. australiensis lineage A, and T. cf. australiensis lineage B. Gonad histology in individuals with ovisacs of lineage A revealed no evidence of testicular tissue; however, large testicular lobes were found in individuals with ovisacs of lineage B, indicating that they were anatomically hermaphrodites. This is the first record of Australian hermaphroditic Triops. For each lineage, a single haplotype of each gene was obtained. Molecular genetic distance and phylogenetic analyses confirmed the closer relationship and monophyly of the two lineages with T. australiensis (GenBank) when compared with Triops species from other continents. COI haplotypes of lineage A and lineage B differed by 7.7% from each other and differed by 10.2% and 9.6% from a published T. australiensis sequence, respectively. The 12S haplotypes of lineage A and lineage B differed by 3.3% from each other and differed by 2% and 2.5% from a published T. australiensis sequence, respectively. Our results suggest that the two co-occurring Triops lineages probably represent two species that are distinct from T. australiensis. 2011-07-20T03:20:03.767Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3792 The cued Go/NoGo task elicits response preparation during the foreperiod, and, depending on the S2 signal, either response execution or inhibition. This study aimed to determine how processes in the foreperiod might affect or predict post-S2 processing. Thirty-two adults participated in a cued Go/NoGo task (50% Go), with a median split of mean RT producing “Fast” and “Slow” groups. ERP measures were subjected to both ANOVA and regression techniques. There were no differences in the NoGo N2 effect related to response speed, nor was the effect related to pre-S2 processes. The anterior shift of the NoGo P3 was larger in the Fast group, and while the late CNV was associated with the absolute amplitude of both Go and NoGo P3, it was not related to the anterior–posterior Go/NoGo differences. Together, these data suggest that the inhibitory process may be reflected in the NoGo P3 effect, rather than the NoGo N2 effect. 2010-05-12T01:50:01.447Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1042 Calibration and prediction in conceptual rainfall-runoff (CRR) modelling is affected by the uncertainty in the observed forcing/response data and the structural error in the model. This study works towards the goal of developing a robust framework for dealing with these sources of error and focuses on model error. The characterisation of model error in CRR modelling has been thwarted by the convenient but indefensible treatment of CRR models as deterministic descriptions of catchment dynamics. This paper argues that the fluxes in CRR models should be treated as stochastic quantities because their estimation involves spatial and temporal averaging. Acceptance that CRR models are intrinsically stochastic paves the way for a more rational characterisation of model error. The hypothesis advanced in this paper is that CRR model error can be characterised by storm-dependent random variation of one or more CRR model parameters. A simple sensitivity analysis is used to identify the parameters most likely to behave stochastically, with variation in these parameters yielding the largest changes in model predictions as measured by the Nash–Sutcliffe criterion. A Bayesian hierarchical model is then formulated to explicitly differentiate between forcing, response and model error. It provides a very general framework for calibration and prediction, as well as for testing hypotheses regarding model structure and data uncertainty. A case study calibrating a six-parameter CRR model to daily data from the Abercrombie catchment (Australia) demonstrates the considerable potential of this approach. Allowing storm-dependent variation in just two model parameters (with one of the parameters characterising model error and the other reflecting input uncertainty) yields a substantially improved model fit raising the Nash–Sutcliffe statistic from 0.74 to 0.94. Of particular significance is the use of posterior diagnostics to test the key assumptions about the data and model errors. The assumption that the storm-dependent parameters are log-normally distributed is only partially supported by the data, which suggests that the parameter hyper-distributions have thicker tails. The results also indicate that in this case study the uncertainty in the rainfall data dominates model uncertainty. 2010-04-27T06:08:06.667Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:216 Objective: To determine the latency and development of conditional suppression of alpha amplitude and its relationship to behaviour, alpha amplitude (8-13 Hz) was measured in a differential conditioning procedure. Methods: The CS +/- were tones and the US was a photic checkerboard. Alpha amplitude, CNV, RT and verbal responses were recorded from 12 participants. Results: The CS +/- difference in acquisition was greatest from 250 ins before the US. It was greatest from the trial where RT declined and participants could report the CS +/US relationship. There was an amplitude increase in lower band activity 230 ins after the US. This looked like a VEP but was produced by phase-locked activity starting before the US. Conclusions: Predicting the US led to cortical priming. Amplitude change in acquisition is congruent with CNV, RT and verbal performance. Significance: Prediction, expectancy and motor preparation are reflected in changes in alpha activity. These results provide converging evidence for the functional role of 8-10 Hz activity. They complement the emerging picture of the role of alpha activity in cognition, indicating that it extends to the acquisition of predictive knowledge. (c) 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. 2010-04-27T06:00:36.710Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:263 The use of pearl oysters has recently been proposed as an environmental remediation tool in coastal ecosystems. This study quantified the nitrogen, phosphorus and heavy metal content of the tissue and shell of pearl oysters harvested from a small pearl oyster farm at Port Stephens, Australia. Each tonne of pearl oyster material harvested resulted in approximately 703 g metals, 7452 g nitrogen, and 545 g phosphorus being removed from the waters of Port Stephens. Increasing current farm production of 9.8 t yr(-1) to 499 t yr(-1) would balance current nitrogen loads entering Port Stephens from a small Sewage Treatment Plant (STP) located on its southern shores. Furthermore, manipulation of harvest dates to coincide with oyster condition would likely remove substantially greater quantities of nutrients. This study demonstrates that pearl aquaculture may be used to assist in the removal of pollutants from coastal waters while producing a commercially profitable commodity. © 2004 Elsevier Ltd. All rights reserved. 2010-04-27T05:57:03.297Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:535 The embryonic stage in the red-crowned toadlet (Pseudophryne australis) varies among individuals of a clutch in three important features that may be a source for selection: the length of the embryonic period (15-119 days), the stage of development at which hatching occurs (Gosner 24-36) and the size of the tadpole at hatching (21-97 mg). Previous evidence suggests that variation ill the Stage at hatching and the length of the embryonic period is not a facultative response to environmental cues. To ascertain whether the basis for this variation was differential maternal provisioning, we investigated the amount Of variability ill egg sizes, and then the relationship of egg size to the length of embryonic period, stage and mass at hatching. The mean coefficient of variation in egg sizes was 3.9% (range 2.5-8.5%), which is quite high when compared to other amphibians. Egg size was positively related to tadpole size at hatching, and this may have consequeuces for fitness. No relationship was found between egg size and stage at hatching. The relationship between egg size and length of embryonic period varied among clutches, with significant sibship effects evident. The basis for variation ill stage at hatching and length of embryonic period remains unknown, but could relate to factors such as the nutritive value of yolk independent of egg size or possibly genetic factors. 2010-04-27T05:39:02.780Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3321 We present a continuous ~14-yr-long (1985 to 1999) high-resolution record of trace element (Mg, Sr, Ba, U) and stable isotope (δ¹³C, δ¹⁸O) variations in a modern freshwater tufa from northwestern Queensland, Australia. By utilizing the temperature dependence of the δ¹⁸O signal, an accurate chronology was developed for the sampled profile, which allowed a comparison of the chemical records with hydrological and meteorological observations. As a consequence, it was possible to constrain the relevant geochemical processes relating climate variables, such as temperature and precipitation, to their chemical proxies in the tufa record. Temperatures calculated from the Mg concentrations of the tufa samples provide close approximations of average annual water temperature variations. Furthermore, we demonstrate that temporal changes in (Mg/Ca)water can be estimated using an empirically derived equation relating (Mg/Ca)water to the (Sr/Ba) ratio measured in the tufa samples. By means of this relationship, it is theoretically possible to determine the (Mg/Ca) ratio of paleowaters, and hence to derive reliable estimates of former water temperatures from the Mg concentrations of fossil tufas from the study area. Sympathetic variations in Sr, Ba, and δ¹³C along the sampled profile record changes in water chemistry, which are most probably caused by variable amounts of calcite precipitation within the vadose zone of the karst aquifer. This process is thought to be markedly subdued whenever the amount of wet-season precipitation exceeds a given threshold. Accordingly, distinct minima in Sr, Ba, and δ¹³C are interpreted to reflect years with above-average rainfall. The pronounced seasonal and annual variability of the U concentration along the profile is thought to primarily record changes in the U flux from the soil to the water table. We suggest that during intensive rain events U is transported to the phreatic zone by complexing organic colloids, giving rise to conspicuous U maxima in the tufa after above-average wet seasons. This study demonstrates the potential of freshwater tufas to provide valuable information on seasonal temperature and rainfall variations. If tufa deposits turn out to be reasonably resistant to secondary processes, combined investigation of speleothems and tufas from the same area could become a promising approach in future research. While speleothems offer continuous records of long-term paleoenvironmental changes, tufas could provide high-resolution time windows into selected periods of the past. 2010-04-27T05:00:37.347Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3354 Airborne particle number concentrations and size distributions as well as CO and NOx concentrations monitored at a site within the central business district of Brisbane, Australia were correlated with the traffic flow rate on a nearby freeway with the aim of investigating differences between weekday and weekend pollutant characteristics. Observations over a 5-year monitoring period showed that the mean number particle concentration on weekdays was (8.8±0.1)×10³ cm⁻³ and on weekends (5.9±0.2)×10³ cm⁻³—a difference of 47%. The corresponding mean particle number median diameters during weekdays and weekends were 44.2±0.3 and 50.2±0.2 nm, respectively. The differences in mean particle number concentration and size between weekdays and weekends were found to be statistically significant at confidence levels of over 99%. During a 1-year period of observation, the mean traffic flow rate on the freeway was 14.2×10⁴ and 9.6×10⁴ vehicles per weekday and weekend day, respectively—a difference of 48%. The mean diurnal variations of the particle number and the gaseous concentrations closely followed the traffic flow rate on both weekdays and weekends (correlation coefficient of 0.86 for particles). The overall conclusion, as to the effect of traffic on concentration levels of pollutant concentration in the vicinity of a major road (about 100 m) carrying traffic of the order of 10⁵ vehicles per day, is that about a 50% increase in traffic flow rate results in similar increases of CO and NOx concentrations and a higher increase of about 70% in particle number concentration. 2010-04-27T04:54:48.259Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5032 We previously investigated the impact of health area of residence on colon and rectal cancer survival by estimating area-specific relative excess risk of death (RER), stratified by stage at diagnosis. The aims of this study were to quantify errors in colorectal cancer stage obtained from an Australian population-based cancer registry and assess the potential impact of errors in stage on these estimates. For a subset of cases, we compared the cancer registry stage with that from a survey of treating surgeons. We then randomly reallocated all cases to a simulated corrected stage according to the estimated misclassification probabilities and repeated the analysis of area variation stratified by simulated stage 1,000 times. We found 70% agreement between the Registry and Survey stage. This reallocation of the Registry cases by stage resulted in substantial variation in area-specific RERs across the simulated samples. Area variation in survival for localized colon and localized rectal cancer, which were previously statistically significant when classified using Registry stage, appeared no longer to be so. Misclassification of cancer registry stage can have an important impact on estimates of spatial variation in stage-specific colon and rectal cancer survival. If population-based cancer registry data are to be effectively used in evaluating and improving cancer care, the quality of the stage data may need to be improved. 2010-04-27T04:51:04.209Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5409 Aegilops tauschii, the donor of the D genome of hexaploid wheat, is accepted as a major contributor of disease resistance and bread-making quality attributes in cultivated wheat. High molecular weight (HMW) glutenins have a significant effect on the bread-making qualities of cultivated wheat. A large range of allelic variation in 424 Ae. tauschii accessions at the Glu-D1t locus for both x- and y-type glutenin subunits as well as at Glu-D3t was observed with SDS-PAGE using the total endosperm protein fraction. Only 4 accessions revealed more than 2 bands on SDS-PAGE. Seventeen new allelic combinations of both x- and y-type glutenin subunits at GluD-1t and 30 new allelic profiles at Glu-D3 were detected. These combinations comprise some lines with x- or y-type null forms. RP-HPLC analysis of accession Aus 18882, which showed 5 bands when the total endosperm protein fraction was resolved on SDS-PAGE, revealed 2 x-types and 1 y-type subunit banding pattern. RP-HPLC of the gliadin fraction exhibited an omega gliadin-like subunit. SDS-PAGE processing of the gliadin-free fraction of the same accession still exhibited the gliadin-like protein. An N-terminal protein sequence of the first 7 amino acids of the slowest moving novel x- type band of accession Aus18882 indicated its uniqueness, as no entries were found to contain this internal sequence. Demonstration of novel allelic combinations at Glu-D1 and Glu-D3 loci implies the potential for exploiting Ae. tauschii to increase the genetic variability of hexaploid wheat, particularly for bread-making qualities. 2010-04-27T04:49:12.176Z ]]>