391 resultados para Transport barriers


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Attributed to the changing social, political and economic landscape of the ‘knowledge economy’, Australian universities are under pressure to produce researchers that have a variety of skills which meet the demands of an increasingly diverse job market. As a consequence, the Australian PhD now includes a range of doctoral degrees. This paper reports on the experiences of two PhD students engaged in an informally managed research higher degree program described in this paper as a Work Integrated Research Higher Degree (WIRHD). Their learning process shares the attributes from both the traditional PhD program and professional doctorates. However, because of the blended nature of the learning contexts, what students need to manage within the WIRHD is much more complicated than the established RHD programs. An exploratory case study approach exploring experiences, benefits, barriers and coping strategies was conducted with the view to develop a preliminary integrative framework that attempts to explain the various contexts that influence the learning experience of WIRHD candidates. The paper concludes with some recommended strategies for helping WIRHD candidates to manage the challenges associated with their learning process.

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IT Governance (ITG) continues to be a top priority for organizations, public and non-public. While the level of awareness towards ITG is evident, it is hardly manifested in practice. The purpose of this study is to elicit factors that act as barriers to the adoption of formal ITG practice. This qualitative study consists of 9 semi-structured interviews with the key person in charge of ITG adoption and practice within their respective organizations. The interviews were analyzed using thematic content analysis, guided by themes previously obtained from the literature and from an earlier pilot study. Findings obtained supported previous findings and also reveal new factors noticeably absent from the ITG literature. The findings will provide useful input towards the development of a causal model on barriers to formal ITG practice

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In many countries there is a shortage of quality teachers in areas of science, technology, engineering and mathematics (STEM). Additional to the low levels of recruitment is an extraordinary high attrition rate with some 50% of beginning teachers leaving the profession within five years. One solution implemented in several countries has been to encourage mid-career professionals in the area of STEM to become school teachers. These professionals are said to bring to teaching enthusiasm, knowledge and a passion for their subject which will impact engagement and learning by students. However, these career-changers have constructed professional identities and are accustomed to working within a culture of collaboration and inquiry. In contrast, school cultures are quite different and often teaching is a lonely solitary affair with little opportunity for collegial relationships aimed at knowledge building in the context of teaching. Crossing from a culture of STEM to a culture of schools and teaching can be challenging. This study was conducted with 13 teachers who were followed for three years. However, this paper reports on the experiences of one teacher with an engineering background crossing the boundaries from practising STEM to Teaching STEM.

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This paper addresses the problem of scheduling a cane transport system involving both rail transport and road transport, where the road transport operates from several sidings in the rail network. An iterative approach for scheduling the rail transport system has been developed using existing rail transport scheduling tools. The assumption that harvesters serviced by road transport are effectively operating from the rail siding from which their bins are supplied seems a reasonable starting point for the analysis. There is a need to manually modify the schedule to take into account the road transport schedule to ensure that full bins are not collected before the road transport system delivers them back to the rail siding.

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While substantial research on intelligent transportation systems has focused on the development of novel wireless communication technologies and protocols, relatively little work has sought to fully exploit proximity-based wireless technologies that passengers actually carry with them today. This paper presents the real-world deployment of a system that exploits public transit bus passengers’ Bluetooth-capable devices to capture and reconstruct micro- and macro-passenger behavior. We present supporting evidence that approximately 12% of passengers already carry Bluetooth-enabled devices and that the data collected on these passengers captures with almost 80 % accuracy the daily fluctuation of actual passengers flows. The paper makes three contributions in terms of understanding passenger behavior: We verify that the length of passenger trips is exponentially bounded, the frequency of passenger trips follows a power law distribution, and the microstructure of the network of passenger movements is polycentric.

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There is currently little information available about reasons for contraceptive use or non-use among young Australian women and the reasons for choosing specific types of contraceptive methods. A comprehensive life course perspective of women's experiences in using and obtaining contraceptives is lacking, particularly relating to women's perceived or physical barriers to access. This paper presents an analysis of qualitative data gathered from free-text comments provided by women born between 1973 and 1978 as part of their participation in the Australian Longitudinal Study on Women's Health. The Australian Longitudinal Study on Women's Health is a large cohort study involving over 40,000 women from three age groups (aged 18-23, aged 40-45 and aged 70-75) who were selected from the database of Medicare the Australian universal health insurance system in 1995. The women have been surveyed every 3 years about their health by mailed self-report surveys, and more recently online. Written comments from 690 women across five surveys from 1996 (when they were aged 18-23 years) to 2009 (aged 31-36 years) were examined. Factors relating to contraceptive use and barriers to access were identified and explored using thematic analysis. Side-effects, method satisfaction, family timing, and hormonal balance were relevant to young women using contraception. Most women who commented about a specific contraceptive method wrote about the oral contraceptive pill. While many women were positive or neutral about their method, noting its convenience or non-contraceptive benefits, many others were concerned about adverse effects, affordability, method failure, and lack of choice. Negative experiences with health services, lack of information, and cost were identified as barriers to access. As the cohort aged over time, method choice, changing patterns of use, side-effects, and negative experiences with health services remained important themes. Side-effects, convenience, and family timing play important roles in young Australian women's experiences of contraception and barriers to access. Contrary to assumptions, barriers to contraceptive access continue to be experienced by young women as they move into adulthood. Further research is needed about how to decrease barriers to contraceptive use and minimise negative experiences in order to ensure optimal contraceptive access for Australian women.

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Deploying wireless networks in networked control systems (NCSs) has become more and more popular during the last few years. As a typical type of real-time control systems, an NCS is sensitive to long and nondeterministic time delay and packet losses. However, the nature of the wireless channel has the potential to degrade the performance of NCS networks in many aspects, particularly in time delay and packet losses. Transport layer protocols could play an important role in providing both reliable and fast transmission service to fulfill NCS’s real-time transmission requirements. Unfortunately, none of the existing transport protocols, including the Transport Control Protocol (TCP) and the User Datagram Protocol (UDP), was designed for real-time control applications. Moreover, periodic data and sporadic data are two types of real-time data traffic with different priorities in an NCS. Due to the lack of support for prioritized transmission service, the real-time performance for periodic and sporadic data in an NCS network is often degraded significantly, particularly under congested network conditions. To address these problems, a new transport layer protocol called Reliable Real-Time Transport Protocol (RRTTP) is proposed in this thesis. As a UDP-based protocol, RRTTP inherits UDP’s simplicity and fast transmission features. To improve the reliability, a retransmission and an acknowledgement mechanism are designed in RRTTP to compensate for packet losses. They are able to avoid unnecessary retransmission of the out-of-date packets in NCSs, and collisions are unlikely to happen, and small transmission delay can be achieved. Moreover, a prioritized transmission mechanism is also designed in RRTTP to improve the real-time performance of NCS networks under congested traffic conditions. Furthermore, the proposed RRTTP is implemented in the Network Simulator 2 for comprehensive simulations. The simulation results demonstrate that RRTTP outperforms TCP and UDP in terms of real-time transmissions in an NCS over wireless networks.

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There is currently little information available about reasons for contraceptive use or non-use among young Australian women and the reasons for choosing specific types of contraceptive methods. A comprehensive life course perspective of women's experiences in using and obtaining contraceptives is lacking, particularly relating to women's perceived or physical barriers to access. This paper presents an analysis of qualitative data gathered from free-text comments provided by women born between 1973 and 1978 as part of their participation in the Australian Longitudinal Study on Women's Health. The Australian Longitudinal Study on Women's Health is a large cohort study involving over 40,000 women from three age groups (aged 18-23, aged 40-45 and aged 70-75) who were selected from the database of Medicare the Australian universal health insurance system in 1995. The women have been surveyed every 3 years about their health by mailed self-report surveys, and more recently online. Written comments from 690 women across five surveys from 1996 (when they were aged 18-23 years) to 2009 (aged 31-36 years) were examined. Factors relating to contraceptive use and barriers to access were identified and explored using thematic analysis. Side-effects, method satisfaction, family timing, and hormonal balance were relevant to young women using contraception. Most women who commented about a specific contraceptive method wrote about the oral contraceptive pill. While many women were positive or neutral about their method, noting its convenience or non-contraceptive benefits, many others were concerned about adverse effects, affordability, method failure, and lack of choice. Negative experiences with health services, lack of information, and cost were identified as barriers to access. As the cohort aged over time, method choice, changing patterns of use, side-effects, and negative experiences with health services remained important themes. Side-effects, convenience, and family timing play important roles in young Australian women's experiences of contraception and barriers to access. Contrary to assumptions, barriers to contraceptive access continue to be experienced by young women as they move into adulthood. Further research is needed about how to decrease barriers to contraceptive use and minimise negative experiences in order to ensure optimal contraceptive access for Australian women.

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Information Technology (IT) is successfully applied in a diverse range of fields. Though, the field of Medical Informatics is more than three decades old, it shows a very slow progress compared to many other fields in which the application of IT is growing rapidly. The spending on IT in health care is shooting up but the road to successful use of IT in health care has not been easy. This paper discusses about the barriers to the successful adoption of information technology in clinical environments and outlines the different approaches used by various countries and organisations to tackle the issues successfully. Investing financial and other resources to overcome the barriers for successful adoption of HIT is highly important to realise the dream of a future healthcare system with each customer having secure, private Electronic Health Record (EHR) that is available whenever and wherever needed, enabling the highest degree of coordinated medical care based on the latest medical knowledge and evidence. Arguably, the paper reviews barriers to HIT from organisations’ alignment in respect to the leadership; with their stated values when accepting or willingness to consider the HIT as a determinant factor on their decision-making processes. However, the review concludes that there are many aspects of the organisational accountability and readiness to agree to the technology implementation.

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Background Surveillance programs and research for acute respiratory infections in remote Australian communities are complicated by difficulties in the storage and transport of frozen samples to urban laboratories for testing. This study assessed the sensitivity of a simple method for transporting nasal swabs from a remote setting for bacterial polymerase chain reaction (PCR) testing. Methods We sampled every individual who presented to a remote community clinic over a three week period in August at a time of low influenza and no respiratory syncytial virus activity. Two anterior nasal swabs were collected from each participant. The left nare specimen was mailed to the laboratory via routine postal services. The right nare specimen was transported frozen. Testing for six bacterial species was undertaken using real-time PCR. Results One hundred and forty participants were enrolled who contributed 150 study visits and paired specimens for testing. Respiratory illnesses accounted for 10% of the reasons for presentation. Bacteria were identified in 117 (78%) presentations for 110 (79.4%) individuals; Streptococcus pneumoniae and Haemophilus influenzae were the most common (each identified in 58% of episodes). The overall sensitivity for any bacterium detected in mailed specimens was 82.2% (95% CI 73.6, 88.1) compared to 94.8% (95% CI 89.4, 98.1) for frozen specimens. The sensitivity of the two methods varied by species identified. Conclusion The mailing of unfrozen nasal specimens from remote communities appears to influence the utility of the specimen for bacterial studies, with a loss in sensitivity for the detection of any species overall. Further studies are needed to confirm our finding and to investigate the possible mechanisms of effect. Clinical trial registration Australia and New Zealand Clinical Trials Registry Number: ACTRN12609001006235. Keywords: Respiratory bacteria; RT-PCR; Specimen transport; Laboratory methods

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OBJECTIVE: School-aged youth spend a significant amount of time either in transit to and from school, or within school settings performing a range of varying learning-based activities. Adolescent physical activity has also been shown to increase the likelihood of maintaining physical activity throughout adulthood. The purpose of this study is to investigate adolescents’ perceived school-based barriers and facilitators to engagement in physical activity. METHODS: One-hundred and twenty four participants (38 males and 86 females) were recruited from two non-denominational same-sex private schools, in Brisbane, Australia. The mean age and standard deviation (SD) was 13.83 (0.56) and 14.40 (2.33) for males and females respectively. Participants responded to a series questions regarding perceived barriers and facilitators to engagement in physical activity. Quantitative data was analysed using descriptive statistics and frequency distributions, and qualitative data with thematic analysis. RESULTS: A total of 121 (97.6%) participants had complete data sets and were included in the analysis. School timetable (44.6%), homework (81.8%), and assessment (81.0%) were identified as the most prominent perceived factors, increasing the difficulty of physical activity engagement. Physical Education classes (71.9%) and school sport programs (80.2%) were identified as the most prominent perceived factors that facilitate engagement in physical activity. There was no significant gender effect. CONCLUSIONS: Each of the identified factors perceived by adolescent's as either barriers or facilitators to engagement in physical activity may be addressed by administrators at a school and government policy level. These may include strategies such as; increasing the assigned hours to physical education classes, providing additional extra-curricular sporting opportunities, and reviewing the time allocated to homework and assessment items. This may provide a simpler, low-cost solution to increasing youth physical activity, as opposed to contemporary higher-cost strategies utilising increased staff commitment, mass media, provision of equipment and counsellors and other health professionals.

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Due to the chronic shortages of GPs in Australian rural and remote regions, considerable numbers of international medical graduates (IMG) have been recruited. IMG experience many difficulties when relocating to Australia with one of the most significant being effective GP-patient communication. Given that this is essential for effective consultation it can have a substantial impact on health care. A purposive sample of seven practising GPs (five IMG, two Australian-trained doctors (ATD)) was interviewed using a semistructured face-to-face interviewing technique. GPs from Nigeria, Egypt, United Kingdom, India, Singapore and Australia participated. Interviews were transcribed and then coded. The authors used qualitative thematic analysis of interview transcripts to identify common themes. IMG-patient communication barriers were considered significant in the Wheatbelt region as identified by both IMG and ATD. ATD indicated they were aware of IMG-patient communication issues resulting in subsequent consults with patients to explain results and diagnoses. Significantly, a lack of communication between ATD and IMG also emerged, creating a further barrier to effective communication. Analysis of the data generated several important findings that rural GP networks should consider when integrating new IMG into the community. Addressing the challenges related to cross-cultural differences should be a priority, in order to enable effective communication. More open communication between ATD and IMG about GP-patient communication barriers and education programs around GP-patient communication would help both GP and patient satisfaction.

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The work presented in this thesis investigates the mathematical modelling of charge transport in electrolyte solutions, within the nanoporous structures of electrochemical devices. We compare two approaches found in the literature, by developing onedimensional transport models based on the Nernst-Planck and Maxwell-Stefan equations. The development of the Nernst-Planck equations relies on the assumption that the solution is infinitely dilute. However, this is typically not the case for the electrolyte solutions found within electrochemical devices. Furthermore, ionic concentrations much higher than those of the bulk concentrations can be obtained near the electrode/electrolyte interfaces due to the development of an electric double layer. Hence, multicomponent interactions which are neglected by the Nernst-Planck equations may become important. The Maxwell-Stefan equations account for these multicomponent interactions, and thus they should provide a more accurate representation of transport in electrolyte solutions. To allow for the effects of the electric double layer in both the Nernst-Planck and Maxwell-Stefan equations, we do not assume local electroneutrality in the solution. Instead, we model the electrostatic potential as a continuously varying function, by way of Poisson’s equation. Importantly, we show that for a ternary electrolyte solution at high interfacial concentrations, the Maxwell-Stefan equations predict behaviour that is not recovered from the Nernst-Planck equations. The main difficulty in the application of the Maxwell-Stefan equations to charge transport in electrolyte solutions is knowledge of the transport parameters. In this work, we apply molecular dynamics simulations to obtain the required diffusivities, and thus we are able to incorporate microscopic behaviour into a continuum scale model. This is important due to the small size scales we are concerned with, as we are still able to retain the computational efficiency of continuum modelling. This approach provides an avenue by which the microscopic behaviour may ultimately be incorporated into a full device-scale model. The one-dimensional Maxwell-Stefan model is extended to two dimensions, representing an important first step for developing a fully-coupled interfacial charge transport model for electrochemical devices. It allows us to begin investigation into ambipolar diffusion effects, where the motion of the ions in the electrolyte is affected by the transport of electrons in the electrode. As we do not consider modelling in the solid phase in this work, this is simulated by applying a time-varying potential to one interface of our two-dimensional computational domain, thus allowing a flow field to develop in the electrolyte. Our model facilitates the observation of the transport of ions near the electrode/electrolyte interface. For the simulations considered in this work, we show that while there is some motion in the direction parallel to the interface, the interfacial coupling is not sufficient for the ions in solution to be "dragged" along the interface for long distances.

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Road safety barriers are used to redirect traffic at roadside work-zones. When filled with water, these barriers are able to withstand low to moderate impact speeds up to 50kmh-1. Despite this feature, Portable Water-filled barriers (PWFB) face challenges such as large lateral displacements, tearing and breakage during impact; especially at higher speeds. This study explores the use of composite action to enhance the crashworthiness of PWFBs and enable their usage at higher speeds. Initially, energy absorption capability of water in PWFB is investigated. Then, composite action of the PWFB with the introduction of steel frame is considered to evaluate its enhanced impact performance. Findings of the study show that the initial height of the impact must be lower than the free surface level of water in a PWFB in order for the water to provide significant crash energy absorption. In general, an impact of a road barrier with 80% filled is a good estimation. Furthermore, the addition of a composite structure greatly reduces the probability of tearing by decreasing the strain and impact energy transferred to the shell container. This allows the water to remain longer in the barrier to absorb energy via inertial displacements and sloshing response. Information from this research will aid in the design of new generation roadside safety structures aimed to increase safety in modern roadways.

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An accurate evaluation of the airborne particle dose-response relationship requires detailed measurements of the actual particle concentration levels that people are exposed to, in every microenvironment in which they reside. The aim of this work was to perform an exposure assessment of children in relation to two different aerosol species: ultrafine particles (UFPs) and black carbon (BC). To this purpose, personal exposure measurements, in terms of UFP and BC concentrations, were performed on 103 children aged 8-11 years (10.1 ± 1.1 years) using hand-held particle counters and aethalometers. Simultaneously, a time-activity diary and a portable GPS were used to determine the children’s daily time-activity pattern and estimate their inhaled dose of UFPs and BC. The median concentration to which the study population was exposed was found to be comparable to the high levels typically detected in urban traffic microenvironments, in terms of both particle number (2.2×104 part. cm-3) and BC (3.8 μg m-3) concentrations. Daily inhaled doses were also found to be relatively high and were equal to 3.35×1011 part. day-1 and 3.92×101 μg day-1 for UFPs and BC, respectively. Cooking and using transportation were recognized as the main activities contributing to overall daily exposure, when normalized according to their corresponding time contribution for UFPs and BC, respectively. Therefore, UFPs and BC could represent tracers of children exposure to particulate pollution from indoor cooking activities and transportation microenvironments, respectively.