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Offshore wind farms are a current area of interest in Australia due to their ability to support its transition to renewable energy. Climate reanalysis datasets that provide simulated wind speed data are frequently used to evaluate the potential of proposed offshore wind farm locations. However, there has been a lack of comparative studies of the accuracy of wind speed predictions from different reanalysis datasets for offshore wind farms in Australian waters. This paper assesses wind speed distribution accuracy and compares predictions of offshore wind turbine power output in Australia from three international reanalysis datasets: BARRA, ERA5, and MERRA-2. Pressure level data were used to determine wind speeds and capacity factors were calculated using a turbine bounding curve. Predictions across the datasets show consistent spatial and temporal variations in the predicted plant capacity factors, but the magnitudes differ substantially. Compared to weather station data, wind speed predictions from the BARRA dataset were found to be the most accurate, with a higher correlation and lower average error than ERA5 and MERRA-2. Significant variation was seen in predictions and there was a lack of similarity with weather station measurements, which highlights the need for additional site-based measurements. [ABSTRACT FROM AUTHOR]

• Apply python to interface with plaxis software to simulate the embankment settlement for a case study in Australia. • Develope a GEP-based prediction model to estimate the settlement of ground improvement. • Conduct a parametric study to examine the effects of input variables on the settlement of the ground. • Optimize the design of CMC diameters and CMC spacings for specific ground conditions. This paper is going to present the advanced feature in Plaxis using remote scripting with Python wrapper. Python allows engineers to create Plaxis models, calculate construction phases, and plot the results automatically. The settlement estimation of a high embankment, supported by cement mixing columns (CMC), is presented as a case study. Approximately 500 models were created and analyzed within a few hours with different embankment heights, soft soil thickness, CMC spacing, and CMC diameter. This original database was used to develop a regression model using a Gene-expression programming (GEP) algorithm. The proposed GEP-based model with high accuracy could be applied to optimize the CMC design. In detail, the coefficient of correlation (R-value) of all phases is high and fluctuates from 0.967 to 0.976, while the mean absolute error of the model is lower than 0.009 m. The parametric study indicates that increasing the height of the fill embankment, the thickness of the peat layer, or the spacing between CMCs causes high settlement, while increasing the CMC diameter could significantly reduce the settlement of the embankment. The research results demonstrate that using Plaxis remote scripting and the GEP technique could help engineers run the numerical analysis much faster, leading to a more in-depth analysis to create better decision-making. [ABSTRACT FROM AUTHOR]

This paper introduces a novel model for predicting the performance and conducting sensitivity analysis of design parameters in two-body point absorber wave energy converters. The key novelty lies in the examination of design parameter sensitivity and their interaction effects on performance. The model utilizes the response surface method (RSM) in conjunction with central composite design to establish analytical equations for efficiently predicting the resonance frequency and peak generated power of the two-body wave energy converters based on geometric parameters and wave height. This eliminates the need for complex analytical solutions and boundary element simulations. The accuracy and reliability of the RSM prediction models are validated through state-of-the-art numerical simulations and analysis of variance (ANOVA). Using these RSM prediction models, the study proceeds to design and optimize two-body point absorbers for locations along the coastlines of the six Australian states, focusing on two objectives: maximizing peak output power and maximizing the power-to-weight ratio at each location. By incorporating the second optimization target, it is observed that impressive power output with smaller device dimensions or a higher power-to-weight ratio can be achieved across all six Australian states. The developed response surface method prediction model is a versatile mathematical framework applicable to all two-body point absorber wave energy converters and can be adapted for optimizing other types of wave energy converters with expansive search spaces. Australia was selected as a case study due to its abundant wave energy density along its southern shorelines. Notably, no similar studies addressing these specific aspects have been reported in the literature, making this work the first of its kind. • The performance prediction models of two body wave energy converters have been developed from design parameters. • The prediction models are validated against numerical simulations and the analysis of variance (ANOVA). • The sensitivity of design parameters and their interactions has been analyzed and disclosed. • The optimal dimensions for the maximum power and maximum power to weight ratio are derived for all the Australian seas. [ABSTRACT FROM AUTHOR]

To stabilise the tunnel faces and slopes in soft clay for the Airport Link construction in Australia, fracture grouting and glass fibre-reinforced plastic (GFRP) soil nails are proposed for the soil improvement as well as ease of handling. The compensation caused by the fracture grouting and the gain in strength due to consolidation as well as the geonail have stabilised the soft clay during construction. Only a small amount of ground settlement during soft clay box-jacking operation is generated so that the railway traffic above the embankment can be maintained without interference. The design method of the fracture grouting ground improvement study for this difficult project is discussed in this paper. Extensive laboratory and field tests were employed to verify the design assumptions and to fine-tune the ground improvement studies. The success of this project in poor ground conditions results from combined efforts of extensive field tests, an improved ground improvement design method and a realistic numerical analysis to assess the unstable/highly stressed zones for the placement of soil reinforcement. [ABSTRACT FROM AUTHOR]

Performance evaluation of multi-target tracking algorithms is of great practical importance in the design, parameter optimization and comparison of tracking systems. The goal of performance evaluation is to measure the distance between two sets of tracks: the ground truth tracks and the set of estimated tracks. This paper proposes a mathematically rigorous metric for this purpose. The basis of the proposed distance measure is the recently formulated consistent metric for performance evaluation of multi-target filters, referred to as the OSPA metric. Multi-target filters sequentially estimate the number of targets and their position in the state space. The OSPA metric is therefore defined on the space of finite sets of vectors. The distinction between filtering and tracking is that tracking algorithms output tracks and a track represents a labeled temporal sequence of state estimates, associated with the same target. The metric proposed in this paper is therefore defined on the space of finite sets of tracks and incorporates the labeling error. Numerical examples demonstrate that the proposed metric behaves in a manner consistent with our expectations. [ABSTRACT FROM PUBLISHER]

In a recent Australian homicide, trace soil on the victim's clothing suggested she was initially attacked in her front yard and not the park where her body was buried. However the important issue that emerged during the trial was how soil was transferred to her clothing. This became the catalyst for designing a range of soil transference experiments (STEs) to study, recognise and classify soil patterns transferred onto fabric when a body is dragged across a soil surface. Soil deposits of interest in this murder were on the victim's bra and this paper reports the results of anthropogenic soil transfer to bra-cups and straps caused by dragging. Transfer patterns were recorded by digital photography and photomicroscopy. Eight soil transfer patterns on fabric, specific to dragging as the transfer method, appeared consistently throughout the STEs. The distinctive soil patterns were largely dependent on a wide range of soil features that were measured and identified for each soil tested using X-ray Diffraction and Non-Dispersive Infra-Red analysis. Digital photographs of soil transfer patterns on fabric were analysed using image processing software to provide a soil object-oriented classification of all soil objects with a diameter of 2 pixels and above transferred. Although soil transfer patterns were easily identifiable by naked-eye alone, image processing software provided objective numerical data to support this traditional (but subjective) interpretation. Image software soil colour analysis assigned a range of Munsell colours to identify and compare trace soil on fabric to other trace soil evidence from the same location; without requiring a spectrophotometer. Trace soil from the same location was identified by linking soils with similar dominant and sub-dominant Munsell colour peaks. Image processing numerical data on the quantity of soil transferred to fabric, enabled a relationship to be discovered between soil type, clay mineralogy (smectite), particle size and soil moisture content that would not have been possible otherwise. Soil type (e.g. Anthropogenic, gravelly sandy loam soil or Natural, organic-rich soil), clay mineralogy (smectite) and soil moisture content were the greatest influencing factors in all the dragging soil transference tests (both naked eye and measured properties) to explain the eight categories of soil transference patterns recorded. This study was intended to develop a method for dragging soil transference laboratory experiments and create a baseline of preliminary soil type/property knowledge. Results confirm the need to better understand soil behaviour and properties of clothing fabrics by further testing of a wider range of soil types and clay mineral properties. [ABSTRACT FROM AUTHOR]

Abstract: Surface–groundwater (SW–GW) interactions constitute a critical proportion of the surface and groundwater balance especially during dry conditions. Conjunctive management of surface and groundwater requires an explicit account of the exchange flux between surface and groundwater when modelling the two systems. This paper presents a case study in the predominantly gaining Boggabri–Narrabri reach of the Namoi River located in eastern Australia. The first component of the study uses the Upper Namoi numerical groundwater model to demonstrate the importance of incorporating SW–GW interactions into river management models. The second component demonstrates the advantages of incorporating groundwater processes in the Namoi River model. Results of the numerical groundwater modelling component highlighted the contrasting groundwater dynamics close to, and away from the Namoi River where lower declines were noted in a near-field well due to water replenishment sourced from river depletion. The contribution of pumping activities to river depletion was highlighted in the results of the uncertainty analysis, which showed that the SW–GW exchange flux is the most sensitive to pumping rate during dry conditions. The uncertainty analysis also showed that after a drought period, the 95% prediction interval becomes larger than the simulated flux, which implies an increasing probability of losing river conditions. The future prospect of a gaining Boggabri–Narrabri reach turning into losing was confirmed with a hypothetical extended drought scenario during which persistent expansion of groundwater pumping was assumed. The river modelling component showed that accounting for SW–GW interactions improved the predictions of low flows, and resulted in a more realistic calibration of the Namoi River model. Incorporating SW–GW interactions into river models allows explicit representation of groundwater processes that provides a mechanism to account for the impacts of additional aquifer stresses that may be introduced beyond the calibration period of the river model. Conventional river models that neglect the effects of such future stresses suffer from the phenomenon of non-stationarity and hence have inferior low flow predictions past the calibration period of the river model. The collective knowledge acquired from the two modelling exercises conducted in this study leads to a better understanding of SW–GW interactions in the Namoi River thus leading to improved water management especially during low flow conditions. [Copyright &y& Elsevier]

Abstract: This paper presents a numerical simulation study that demonstrates history matching and production prediction for an actual horizontal coalbed methane (CBM) well located in Australia. A brief analysis of limited core analysis and well log data is presented. Numerical reservoir simulation is used to carry out a manual history matching to the field data of gas and water production rates and well bottomhole pressure. The matching parameters are porosity, relative permeability and skin factor. The reported field data show that there are sharp changes in the well bottomhole pressure and water and gas rates. This response of the reservoir is matched with a numerical model that has a varying skin factor along the horizontal well. This is deemed reasonable given that the drilling fluid has longer contact with the formation at the heel of the well, causing more formation damage. But the field data indicates that the formation damage is mitigated quickly with production. This is explained by the fact that the invaded mud is forced back during water and gas production and coal shrinkage. The production predictions show that skin factor and coal shrinkage have important effects on the CBM production of a horizontal well. However, the coal formation damage controls the gas rate more than the shrinkage for the examined case study with the assumed coal shrinkage parameters. [Copyright &y& Elsevier]

In boats used for competitive rowing it is traditional for the rowers to use strokes in which the angle between the oar shaft and the perpendicular to the hull centre line is much greater at the catch than it is at the end of the power stroke. As a result, the oar blade is even more inefficient in its action at the catch than it is at the end of the power stroke. This paper shows how boat performance in a race would be improved by reducing the difference in these starting and finishing angles. The claim of improved race performance is supported by a detailed investigation of the dynamics involved in the case of a particular coxless pair whose performance has been recorded by the Australian Institute of Sport. We also suggest an easy way to make the necessary change in boat design. [ABSTRACT FROM AUTHOR]

Abstract: The approach taken in this paper, namely synthesising a wealth of previous information with new data and a genetic model, in combination with integrated numerical analyses, led to new insights into the geological controls on the localisation of auriferous veins and residual prospectivity of the Charters Towers goldfield, NE Australia. The method also has implications for the assessment of other “mature” goldfields worldwide. Despite a number of different ore controls having operated within the Charters Towers goldfield, the controlling factors can be linked to a single genetic model for orogenic, granitoid-hosted lode-gold mineralisation in a brittle deformation regime (D4) of NE–SW to NNE–SSW shortening, under conditions of supralithostatic fluid pressure and low stress difference. Spatial autocorrelation results suggest district-scale alignment of the auriferous veins parallel to and overlapping with the ESE–WNW- to E–W-striking Charters Towers–Ravenswood lineament, a major crustal boundary in the basement to the Ravenswood batholith. At the camp-scale, auriferous veins have abundance and proximity relationships with NW–SE-, NNW–SSE-, NE–SW- and ENE–WSW-oriented lineaments, suggesting that structures that controlled gold deposition in one camp did not necessarily control mineralisation in other camps. Fractal dimensions obtained with the box-counting method range from 1.02 to 1.10, whereas veins in the Charters Towers City camp are characterised by a significantly higher fractal dimension of 1.28. This discrepancy may be taken to imply that most or all outcropping and near-surface deposits within the Charters Towers City camp have been found and that new discoveries are more likely to occur at greater levels of depth, or outside the boundaries of this camp. The new understanding has implications for the assessment of the residual prospectivity of the Charters Towers goldfield, where large areas of prospective rock types and structures (e.g., approximately 40% of the Charters Towers–Ravenswood lineament) are hidden under cover. This parameter space was inaccessible to the historic prospectors and has received relatively little attention from recent explorers. The following steps are suggested for the development of a targeting strategy for lode-gold exploration in areas of the goldfield under cover: (1) identify from geological and geophysical data the ENE–WSW (±15°) and NNW–SSE (±15°) striking structures and geological boundaries within a 20-km-wide corridor parallel to and centred upon the Charters Towers–Ravenswood lineament, the potential control on gold deposit distribution at the regional- to district-scale, (2) interpret from geological and geophysical data the distribution of pre-Middle Devonian granitoids within these areas that are the preferred host rocks of the payable gold deposits, (3) deduce from geophysical data the ENE–WSW (±15°) and NNW–SSE (±15°) striking structures that cut or bound the intrusions identified in step 2, (4) locate segments along the structures identified in step 3 that deviate most from the geometry of a straight line (e.g., potential bends or splays) and/or intersect other structures or geological contacts, or both, and (5) define and rank potential targets within the prospective areas identified in step 4 and systematically test the best ones. [Copyright &y& Elsevier]

• A framework for aggregating large-scale prosumers in electricity markets is proposed. • The proposed bi-level framework is linearized by duality theory and big-M method. • Cases studies based on 120,000 prosumers from Australia are conducted. • Increasing prosumers enlarges the gap between strategic and non-strategic bidding. Increased penetration of distributed energy resources is unleashing the flexibility of large-scale prosumers in deregulated markets. To explore prosumers' potential market revenues, some existing studies have focused on the strategic bidding of prosumers aggregation. A majority of those studies assume the price-taker role of the aggregator while a few studies assume the price-maker role of the aggregator. However, it remains an open question as to how the increasing number of prosumers influences the profit of a strategic aggregator. Therefore, we conduct a numerical analysis in this paper to quantify the profits of aggregating large-scale prosumers. A stochastic bi-level optimization model is proposed to depict the strategic behavior of prosumers aggregation bidding in joint energy and regulation markets. This bi-level model is transformed into a mixed-integer linear programming model by employing the Karush-Kuhn-Tucker conditions based on strong duality theory. Case studies based on 120,000 prosumers from Australia demonstrate that the strategic bidding behavior of an aggregator can lead to a 7.5% decrease in operation costs, and increasing the number of prosumers will lead to a larger gap between non-strategic and strategic behavior. [ABSTRACT FROM AUTHOR]