Effect of soil parameter uncertainty on seismic response of buried segmented pipeline

Pipelines are important lifeline facilities spread over a large area and they generally encounter a range of seismic hazards and different soil conditions. The seismic response of a buried segmented pipe depends on various parameters such as the type of buried pipe material and joints, end restraint conditions, soil characteristics, burial depths, and earthquake ground motion, etc. This study highlights the effect of the variation of geotechnical properties of the surrounding soil on seismic response of a buried pipeline. The variations of the properties of the surrounding soil along the pipe are described by sampling them from predefined probability distribution. The soil-pipe interaction model is developed in OpenSEES. Nonlinear earthquake time-history analysis is performed to study the effect of soil parameters variability on the response of pipeline. Based on the results, it is found that uncertainty in soil parameters may result in significant response variability of the pipeline.

The effect of lumbar support on the trunk muscle activity and pelvic tilt in a passenger vehicle car seat

In order to gain a competitive edge in the market, automotive manufacturers and automotive seat suppliers have identified seat ergonomics for further development to improve overall vehicle comfort. Adjustable lumbar support devices have been offered since long as comfort systems in either a 2-way or 4-way adjustable configuration, although their effect on lumbar strain is not well documented. The effect of a lumbar support on posture and muscular strain, and therefore the relationship between discomfort and comfort device parameter settings, requires clarification. The aim of this paper is to study the effect of a 4-way lumbar support on lower trunk and pelvis muscle activity, pelvic tilt and spine curvature during a car seating activity. 10 healthy subjects (5 m/f; age 19-39) performed a seating activity in a passenger vehicle with seven different static lumbar support positions. The lumbar support was tested in 3 different height positions in relation to the seatback surface centreline (high, centre, low), each having 2 depths positions (lumbar prominence). An extra depth position was added for the centre position. Posture data were collected using a VICON MX motion capture system and NORAXON DTS goniometers and inclinometer. A rigid-body model of an adjustable car seat with four-way adjustable lumbar support was constructed in UGS Siemens NX and connected to a musculoskeletal model of a seated-human, modelled in AnyBody. Wireless electromyography (EMG) was used to calibrate the musculoskeletal model and assess the relationship between (a) muscular strain and lumbar prominence (normal to seatback surface) respective to the lumbar height (alongside seatback surface), (b) hip joint moment and lumbar prominence (normal to seatback surface) respective to lumbar height (alongside seatback surface) and (c) pelvic tilt and lumbar prominence (normal to seatback surface) respective to the lumbar height (alongside seatback surface). This study was based on the assumption that the musculoskeletal human model was seated at the correct R-Point (SgRP), determined via the occupant packaging toolkit in the JACK digital human model. The effect of the interaction between the driver/car-seat has been investigated for factors resulting from the presence and adjustment of a 4-way lumbar support. The results obtained show that various seat adjustments, and driver’s lumbar supports can have complex influence on the muscle activation, joint forces and moments, all of which can affect the comfort perception of the driver. This study enables the automotive industry to optimise passenger vehicle seat development and design. It further more supports the evaluation of static postural and dynamic seat comfort in normal everyday driving tasks and can be applied for future car design to reduce investment and improve comfort.

Concerns about the rollout of broadband : a legal consideration of Australia’s NBN greenfield policy

This paper examines the Australian federal government’s proposal that developers take the primary role for deploying the National Broadband Network (‘NBN’) in greenfield estates. It identifies issues facing the NBN’s implementation and concerns raised by industry. A failure to address these concerns may lessen industry support as well as adversely impact on consumers as NBN implementation costs are passed onto them. The author identifies the need for NBN legislation to clearly establish what is a ‘greenfield estate’; how and when exemptions from implementation obligations will apply; and that NBN services must be treated the same as any other utility service.

Property, planning and purpose : legal concerns facing broadband rollout in Australia

The Australian government, and opposition, are committed to facilitating high-speed broadband provision. In April 2009 the (then) Labor government announced a proposal to facilitate provision by mandating “…the use of fibre optic infrastructure … in greenfield estates ….” Separately, the installation of (usually overhead) cables commenced in select brownfield areas throughout Australia. In the lead up to the 2010 federal election, the broadband policy focus of the (then) federal opposition was to enabling private investment rather than direct investment by government itself. High-speed broadband is essential for Australia’s economic future. Whether implementation is undertaken by government, government owned corporations or private investors, will impact on the processes to be followed. Who does what, also will determine the rights available to land owners. The next stage, of necessity, will involve the establishment of procedures to require the retrofitting of existing urban environments. This clearly will have major property, property rights and valuation impacts. As Horan (2000) observed “…preserving... unique characteristics … of…regions requires a compromise between economic ambitions and social, cultural, and environmental values”. The uncertainty following the federal election, and the influence of independants with individual agendas; presents unique challenges for broadband implementation. This paper seeks to identify the processes to be followed by various potential broadband investors as they work to establish a ubiquitous network. It overviews current legislative regimes and examines concerns raised by stakeholders in various government reviews. It concludes by plotting a clear way forward to the future, with particular regard to property rights and usage.

Design and implementation of wideband baluns for Archimedean spiral antennas

The demand for high-speed data services for portable device has become a driving force for development of advanced broadband access technologies. Despite recent advances in broadband wireless technologies, there remain a number of critical issues to be resolved. One of the major concerns is the implementation of compact antennas that can operate in a wide frequency band. Spiral antenna has been used extensively for broadband applications due to its planar structure, wide bandwidth characteristics and circular polarisation. However, the practical implementation of spiral antennas is challenged by its high input characteristic impedance, relatively low gain and the need for balanced feeding structures. Further development of wideband balanced feeding structures for spiral antennas with matching impedance capabilities remain a need. This thesis proposes three wideband feeding systems for spiral antennas which are compatible with wideband array antenna geometries. First, a novel tapered geometry is proposed for a symmetric coplanar waveguide (CPW) to coplanar strip line (CPS) wideband balun. This balun can achieve the unbalanced to balanced transformation while matching the high input impedance of the antenna to a reference impedance of 50 . The discontinuity between CPW and CPS is accommodated by using a radial stub and bond wires. The bandwidth of the balun is improved by appropriately tapering the CPW line instead of using a stepped impedance transformer. Next, the tapered design is applied to an asymmetric CPW to propose a novel asymmetric CPW to CPS wideband balun. The use of asymmetric CPW does away with the discontinuities between CPW and CPS without having to use a radial stub or bond wires. Finally, a tapered microstrip line to parallel striplines balun is proposed. The balun consists of two sections. One section is the parallel striplines which are connected to the antenna, with the impedance of balanced line equal to the antenna input impedance. The other section consists of a microstrip line where the width of the ground plane is gradually reduced to eventually resemble a parallel stripline. The taper accomplishes the mode and impedance transformation. This balun has significantly improved bandwidth characteristics. Characteristics of proposed feeding structures are measured in a back-to-back configuration and compared to simulated results. The simulated and measured results show the tapered microstrip to parallel striplines balun to have more than three octaves of bandwidth. The tapered microstrip line to parallel striplines balun is integrated with a single Archimedean spiral antenna and with an array of spiral antennas. The performance of the integrated structures is simulated with the aid of electromagnetic simulation software, and results are compared to measurements. The back-to-back microstrip to parallel strip balun has a return loss of better than 10 dB over a wide bandwidth from 1.75 to 15 GHz. The performance of the microstrip to parallel strip balun was validated with the spiral antennas. The results show the balun to be an effective mean of feeding network with a low profile and wide bandwidth (2.5 to 15 GHz) for balanced spiral antennas.

Submission to House Standing Committee on Infrastructure and Communications : inquiry into the role and potential of the National Broadband Network

Just as telecommunications has played a key role in the global economy,1 high-speed broadband will have a significant role to play in the future of the digital economy. In particular high-speed broadband will have a role to play in the delivery of applications and services necessary for acquiring, and maintaining into the future Australia and Australians’ appropriate education level; community; health services, information provision and support; government services and engagement and participation by the public in the political process.

In search of the Korean digital wave

This article sets the context for this special themed issue on the 'Korean digital wave' by considering the symbiotic relationship between digital technologies, their techniques and practices, their uses and the affordances they provide, and Korea's 'compressed modernity' and swift industrialisation. It underscores the importance of interrogating a range of groundbreaking developments and innovations within Korea's digital mediascapes, and its creative and cultural industries, in order to gain a complex understanding of one of Australia's most significant export markets and trading partners. Given the financial and political commitment in Australia to a high-speed broadband network that aims to stimulate economic and cultural activity, recent technological developments in Korea, and the double-edged role played by government policy in shaping the 'Korean digital wave', merit close attention from media and communications scholars.

Inherent errors in pollutant build-up estimation in considering urban land use as a lumped parameter

Stormwater quality modelling results is subject to uncertainty. The variability of input parameters is an important source of overall model error. An in-depth understanding of the variability associated with input parameters can provide knowledge on the uncertainty associated with these parameters and consequently assist in uncertainty analysis of stormwater quality models and the decision making based on modelling outcomes. This paper discusses the outcomes of a research study undertaken to analyse the variability related to pollutant build-up parameters in stormwater quality modelling. The study was based on the analysis of pollutant build-up samples collected from 12 road surfaces in residential, commercial and industrial land uses. It was found that build-up characteristics vary appreciably even within the same land use. Therefore, using land use as a lumped parameter would contribute significant uncertainties in stormwater quality modelling. Additionally, it was also found that the variability in pollutant build-up can also be significant depending on the pollutant type. This underlines the importance of taking into account specific land use characteristics and targeted pollutant species when undertaking uncertainty analysis of stormwater quality models or in interpreting the modelling outcomes.

A prospective study of pregnancy weight gain in Australian women

Background: While weight gain during pregnancy is regarded as important, there has not been a prospective study of measured weight gain in pregnancy in Australia. This study aimed to prospectively evaluate pregnancy-related weight gain against the Institute of Medicine (IOM) recommendations in women receiving antenatal care in a setting where ongoing weight monitoring is not part of routine clinical practice, to describe women's knowledge of weight gain recommendations and to describe the health professional advice received relating to gestational weight gain (GWG). Methods: Pregnant women were recruited ≤20 weeks of gestation (n = 664) from a tertiary obstetric hospital between August 2010 to July 2011 for this prospective observational study. Outcome measures were weight gain from pre-pregnancy to 36 weeks of gestation, weight gain knowledge and health professional advice received. Results: Thirty-six percent of women gained weight according to guidelines. Twenty-six percent gained inadequate weight, and 38% gained excess weight. Fifty-six percent of overweight women gained weight in excess of the IOM guidelines compared with 30% of those who started with a healthy weight (P < 0.001). At 16 weeks, 47% of participants were unsure of the weight gain recommendations for them. Sixty-two percent of women reported that the health professionals caring for them during this pregnancy ‘never’ or ‘rarely’ offered advice about how much weight to gain. Conclusions: The prevalence of inappropriate gestational weight gain in this study was high. The majority of women do not know their recommended weight gain. The advice women received from health professionals relating to healthy weight gain in pregnancy could be improved.

Weight gain and nutritional intake in obese pregnant women : some clues for intervention

Aim:  Maternal obesity is associated with increased risk of adverse outcomes for mothers and offspring. Strategies to better manage maternal obesity are urgently needed; however, there is little evidence to assist the development of nutrition interventions during antenatal care. The present study aimed to assess maternal weight gain and dietary intakes of overweight and obese women participating in an exercise trial. Results will assist the development of interventions for the management of maternal overweight and obesity. Methods:  Fifty overweight and obese pregnant women receiving antenatal care were recruited and provided dietary and weight data at baseline (12 weeks), 28 weeks, 36 weeks gestation and 6 weeks post-partum. Data collected were compared with current nutritional and weight gain recommendations. Associations used Pearson's correlation coefficient, and ANOVA assessed dietary changes over time, P < 0.05. Results:  Mean prepregnancy body mass index was 34.4 ± 6.6 kg/m2. Gestational weight gain was 10.6 ± 6 kg with a wide range (−4.1 to 23.0 kg). 52% of women gained excessive weight (>11.5 kg for overweight and >9 kg for obese women). Gestational weight gain correlated with post-partum weight retention (P < 0.001). Dietary intakes did not change significantly during pregnancy. No women achieved dietary fat or dietary iron recommendations, only 11% achieved adequate dietary folate, and 38% achieved adequate dietary calcium. Very few women achieved recommended food group servings for pregnancy, with 83% consuming excess servings of non-core foods. Conclusion:  Results provide evidence that early intervention and personalised support for obese pregnant women may help achieve individualised goals for maternal weight gain and dietary adequacy, but this needs to be tested in a clinical setting.