Network timing and the 2015 leap second

© Springer International Publishing Switzerland 2016. Using a testbed with reference timestamping, we collected timing data from public Stratum-1 NTP servers during the leap second event of end-June 2015. We found a wide variety of anomalous serverside behaviors, both at the NTP protocol level and in the server clocks themselves, which can last days or even weeks after the event. Out of 176 servers, only 61% had no erroneous behavior related to the leap second event that we could detect

Rot at the roots? Examining public timing infrastructure

© 2016 IEEE. Timekeeping is central to network measurement. In typical systems, its accuracy is ultimately dependent on the forest of timeservers accessible over the network, whose roots are the stratum-1 timeservers, which benefit from reference hardware. It is essential that these servers are accurate and reliable, and it is commonly assumed that this is the case. We put this belief to the test through an examination of around 100 publicly accessible stratum-1 servers, using datasets spanning over 3 years, collected in a testbed with reference timestamping. We develop a methodology capable of disambiguating the effects of routing changes, congestion related variability, and server anomalies on timestamps. We use it to make a first assessment of the health of (public) network timing, by reporting on the type, severity, and frequency of anomalies we encounter

Carers\u27 preferences for the delivery of therapy services for people with disability in rural Australia: Evidence from a discrete choice experiment

Background: The implementation of the Australian National Disability Insurance Scheme (NDIS) is expected to generate a responsive, person-centred system that will empower people with disability to choose the services and support they receive. However little attention has been paid to examine how users of the NDIS will choose and spend their individual budgets. This study aimed to determine quantitatively the relative importance that carers of people with a disability living in rural Australia place on different therapy service delivery characteristics. Methods: A stated preference discrete choice experiment (DCE) was incorporated into a survey of carers of people with disability living in rural Australia. Carers chose between therapy delivery services differing in attributes such as travel time to receive therapy, sector providing the service (i.e. Government, not-for-profit, private), out-of-pocket costs, person who delivers the therapy (therapist or other staff) and waiting time. Results: A total of 133 carers completed the DCE. The majority of respondents cared for a child with a disability (84%), the average age of the person they cared for was 17 years (SD 14.25). Participants expressed strong preferences for a short waiting time (0-3 months) to receive therapy services; services delivered by a therapist, no out of pocket cost and travelling up to 4 hours to receive a therapy session (p Conclusion: Carers of people with a disability in rural Australia exhibited strongest preferences for short waiting times (0-3 months). Therapy services that are delivered by therapy assistants or support workers will require careful introduction to achieve uptake and acceptability

Factors affecting retention of allied health professionals working with people with disability in rural New South Wales, Australia: discrete choice experiment questionnaire development

Objective: This paper describes the development of a discrete choice experiment (DCE) questionnaire to identify the factors (attributes) that allied health professionals (AHPs) working with people with disability identify as important to encouraging them to remain practising in rural areas. Methods: Focus groups and semi-structured interviews were conducted with 97 purposively selected service providers working with people with disability in rural New South Wales, Australia. Focus groups and interviews were digitally recorded, transcribed, and analysed using a modified grounded theory approach involving thematic analysis and constant comparison. Results: Six attributes that may influence AHPs working with people with disability in rural areas to continue to do so were inductively identified: travel arrangements, work flexibility, professional support, professional development, remuneration, and autonomy of practice. The qualitative research information was combined with a policy review to define these retention factors and ensure that they are amenable to policy changes. Conclusion: The use of various qualitative research methods allowed the development of a policy-relevant DCE questionnaire that was grounded in the experience of the target population (AHPs)

Should I stay or should I go? Exploring the job preferences of allied health professionals working with people with disability in rural Australia

Introduction: The uneven distribution of allied health professionals (AHPs) in rural and remote Australia and other countries is well documented. In Australia, like elsewhere, service delivery to rural and remote communities is complicated because relatively small numbers of clients are dispersed over large geographic areas. This uneven distribution of AHPs impacts significantly on the provision of services particularly in areas of special need such as mental health, aged care and disability services. Objective: This study aimed to determine the relative importance that AHPs (physiotherapists, occupational therapists, speech pathologists and psychologists – “therapists”) living in a rural area of Australia and working with people with disability, place on different job characteristics and how these may affect their retention. Methods: A cross-sectional survey was conducted using an online questionnaire distributed to AHPs working with people with disability in a rural area of Australia over a 3-month period. Information was sought about various aspects of the AHPs’ current job, and their workforce preferences were explored using a best–worst scaling discrete choice experiment (BWSDCE). Conditional logistic and latent class regression models were used to determine AHPs’ relative preferences for six different job attributes. Results: One hundred ninety-nine AHPs completed the survey; response rate was 51 %. Of those, 165 completed the BWSDCE task. For this group of AHPs, “high autonomy of practice” is the most valued attribute level, followed by “travel BWSDCE arrangements: one or less nights away per month”, “travel arrangements: two or three nights away per month” and “adequate access to professional development”. On the other hand, the least valued attribute levels were “travel arrangements: four or more nights per month”, “limited autonomy of practice” and “minimal access to professional development”. Except for “some job flexibility”, all other attributes had a statistical influence on AHPs’ job preference. Preferences differed according to age, marital status and having dependent children. Conclusions: This study allowed the identification of factors that contribute to AHPs’ employment decisions about staying and working in a rural area. This information can improve job designs in rural areas to increase retention

Parameter estimation for compact binaries with ground-based gravitational-wave observations using the LALInference software library

The Advanced LIGO and Advanced Virgo gravitational-wave (GW) detectors will begin operation in the coming years, with compact binary coalescence events a likely source for the first detections. The gravitational waveforms emitted directly encode information about the sources, including the masses and spins of the compact objects. Recovering the physical parameters of the sources from the GW observations is a key analysis task. This work describes the LALInference software library for Bayesian parameter estimation of compact binary signals, which builds on several previous methods to provide a well-tested toolkit which has already been used for several studies. We show that our implementation is able to correctly recover the parameters of compact binary signals from simulated data from the advanced GW detectors. We demonstrate this with a detailed comparison on three compact binary systems: a binary neutron star, a neutron star–black hole binary and a binary black hole, where we show a cross comparison of results obtained using three independent sampling algorithms. These systems were analyzed with nonspinning, aligned spin and generic spin configurations respectively, showing that consistent results can be obtained even with the full 15-dimensional parameter space of the generic spin configurations. We also demonstrate statistically that the Bayesian credible intervals we recover correspond to frequentist confidence intervals under correct prior assumptions by analyzing a set of 100 signals drawn from the prior. We discuss the computational cost of these algorithms, and describe the general and problem-specific sampling techniques we have used to improve the efficiency of sampling the compact binary coalescence parameter space

Decision-support system for risk management of produced water in the offshore petroleum industry

A decision-support system for produced water management (DISSPROWM) in offshore operations is being developed. The system determines the risk and hazards to human and marine species from non-carcinogenic and carcinogenic pollutants, including radionuclides present in produced water. The DISSPROWM also evaluates the best available treatment technology for treating the produced water whose properties are in the database. The system consists of a Windows-based Graphical User Interface (GUI) developed with Microsoft Visual Basic, which integrates a SQL Server database, a risk assessment model and a dilution model for produced water contaminants. The database contains most produced water pollutants and their important properties that are required in dispersion and risk assessment modelling. The database also contains current produced water regulations and information on some of the selected existing treatment technologies with typical cost data required in the decision-support system

Children\u27s perceptions of the factors helping them to be resilient to sedentary lifestyles

Despite the increased risk of sedentary lifestyles associated with socioeconomic disadvantage, some children living in disadvantaged areas display 'resilience' to unhealthy behaviours whereby they manage to engage in regular physical activity and avoid high levels of screen time. It is important to understand what is helping these children to do well. This qualitative study explored the perceptions of 'resilient' children regarding factors that assist them to engage in high levels of physical activity and low screen time. In-depth face-to-face interviews were conducted with 38 children (7-13 years) living in disadvantaged neighbourhoods in urban and rural areas of Victoria, Australia. Themes that emerged relating to physical activity included: parental support and encouragement of physical activity, having a supportive physical environment and having friends to be active with. Themes relating to screen time included: individual preferences to be active, knowledge of health risks associated with sedentary behaviour, having a home environment supportive of physical activity and parental rules. The results provide valuable insights regarding factors that may help children living in disadvantaged neighbourhoods to be physically active and reduce their screen time and may inform future studies targeting this important population group.Jenny Veitch, Lauren Arundell, Clare Hume and Kylie Bal