SeqSLAM : visual route-based navigation for sunny summer days and stormy winter nights

Learning and then recognizing a route, whether travelled during the day or at night, in clear or inclement weather, and in summer or winter is a challenging task for state of the art algorithms in computer vision and robotics. In this paper, we present a new approach to visual navigation under changing conditions dubbed SeqSLAM. Instead of calculating the single location most likely given a current image, our approach calculates the best candidate matching location within every local navigation sequence. Localization is then achieved by recognizing coherent sequences of these “local best matches”. This approach removes the need for global matching performance by the vision front-end - instead it must only pick the best match within any short sequence of images. The approach is applicable over environment changes that render traditional feature-based techniques ineffective. Using two car-mounted camera datasets we demonstrate the effectiveness of the algorithm and compare it to one of the most successful feature-based SLAM algorithms, FAB-MAP. The perceptual change in the datasets is extreme; repeated traverses through environments during the day and then in the middle of the night, at times separated by months or years and in opposite seasons, and in clear weather and extremely heavy rain. While the feature-based method fails, the sequence-based algorithm is able to match trajectory segments at 100% precision with recall rates of up to 60%.

Winter Harmonica

Poem

In the Wake of Cyclone Yasi : Facilitation and Evaluation in Community Narrative-Driven Projects

On 3 February 2011, Cyclone Yasi struck the coast of North Queensland, causing widespread damage. The cyclone destroyed the small coastal town of Cardwell, about 165 kilometres north of Townsville, Queensland. This chapter serves as a case study of a collaborative outreach project mobilised in response to this disaster in North Queensland. A public history research team, consisting of practitioners from the Queensland University of Technology’s Creative Industries Faculty, with the support of the Oral History Association of Australia, Queensland branch, partnered with the Cardwell and District Historical Society to support the society to collect community narratives in the wake of Cyclone Yasi.

The benefits of thermal clothing during winter in patients with heart failure : a pilot randomised controlled trial

Background Many Australian cities experience large winter increases in deaths and hospitalisations. Flu outbreaks are only part of the problem and inadequate protection from cold weather is a key independent risk factor. Better home insulation has been shown to improve health during winter, but no study has examined whether better personal insulation improves health. Data and Methods We ran a randomised controlled trial of thermal clothing versus usual care. Subjects with heart failure (a group vulnerable to cold) were recruited from a public hospital in Brisbane in winter and followed-up at the end of winter. Those randomised to the intervention received two thermal hats and tops and a digital thermometer. The primary outcome was the number of days in hospital, with secondary outcomes of General Practitioner (GP) visits and self-rated health. Results The mean number of days in hospital per 100 winter days was 2.5 in the intervention group and 1.8 in the usual care group, with a mean difference of 0.7 (95% CI: –1.5, 5.4). The intervention group had 0.2 fewer GP visits on average (95% CI: –0.8, 0.3), and a higher self-rated health, mean improvement –0.3 (95% CI: –0.9, 0.3). The thermal tops were generally well used, but even in cold temperatures the hats were only worn by 30% of subjects. Conclusions Thermal clothes are a cheap and simple intervention, but further work needs to be done on increasing compliance and confirming the health and economic benefits of providing thermals to at-risk groups.

Computer simulation of the fatigue behaviour of roof cladding during the passage of a tropical cyclone

This paper describes the development of an analytical model used to simulate the fatigue behaviour of roof cladding during the passage of a tropical cyclone. The model incorporated into a computer program uses wind pressure data from wind tunnel tests in combination with time history information on wind speed and direction during a tropical cyclone, and experimental fatigue characteristics data of roof claddings. The wind pressure data is analysed using a rainflow form of analysis, and a fatigue damage index calculated using a modified form of Miner's rule. Some of the results obtained to date and their significance in relation to the review of current fatigue tests are presented. The model appears to be reasonable for comparative estimation of fatigue life, but an improvement of Miner's rule is required for the prediction of actual fatigue life.

Towards an appropriate fatigue loading sequence for roof claddings in cyclone prone areas

Currently two different fatigue tests are being used to investigate the fatigue susceptibility of roof claddings in the cyclone prone areas of Australia. In order to resolve this issue a detailed investigation was conducted to study the nature of cyclonic wind forces using wind tunnel testing and computer modelling and the fatigue behaviour of metal roof claddings using structural testing. This led to the development of an accurate, but complicated loading matrix for a design cyclone. Based on this matrix, a simplified low-high-low loading sequence has been developed for the testing of roofing systems in cyclone prone areas. This paper first reviews the currently used fatigue loading sequences, then presents details of the cyclonic wind loading matrix and finally the development of the new simplified loading sequence. This simplified sequence should become the only suitable test for most of the cyclone prone areas of Australia covered by Region C which suffers from Category 4 cyclones. For Region D which suffers from Category 5 cyclones, the same loading sequence with 20% increased cycles has been recommended. An experimental programme to validate the new simplified loading sequence has been proposed.

Cyclone intensity categories

The weather forecast centers in Australia and many other countries use a scale of cyclone intensity categories (categories 1-5) in their cyclone advisories, which are considered to be indicative of the cyclone damage potential. However, this scale is mainly based on maximum gust wind speeds. In a recent research project involving computer modeling of cyclonic wind forces on roof claddings and fatigue damage to claddings, it was found that cyclone damage not only depends on the maximum gust wind speed, but also on two other cyclone parameters, namely, the forward speed and radius to maximum winds. This paper describes the computer model used in predicting the cyclone damage to claddings and investigates the damage potential of a cyclone as a function of all the relevant cyclone parameters, based on which it attempts to refine the current scale of cyclone intensity categories.

Respiratory illness during winter : a cohort study of urban children from temperate Australia

Objective: To examine the epidemiology and burden of respiratory illness during winter in urban children from temperate Australia. Methods: We conducted a cohort study of healthy Melbourne children, aged from 12 to 71 months. Parents kept a daily respiratory symptom diary and recorded resource use when an influenza-like illness (ILI) occurred. Results: One-hundred and eighteen children had 137 ILI episodes over 12 weeks for a rate of 0.53 ILI episodes per child-month (95% CI 0.44-0.61). Risk factors for ILI included younger age, fewer people residing in the household, structured exposure to other children outside the home, and a higher household income. Episodes had a mean duration of 10.4 days with 64 visits to a general practitioner (46.7 GP visits per 100 episodes), 27 antibiotic courses prescribed (19.7 antibiotic courses per 100 episodes), and three overnight hospitalizations (2.2 admissions per 100 episodes). Parents reported an average of 11.7 h excess time spent caring for a child per episode. Conclusions: Respiratory illnesses are a common and largely neglected cause of illness in Australian children. Pathogen-specific data are required to better assess the likely impact of available and developing vaccines and other treatment options.

Anatomy of sand beach ridges : evidence from severe Tropical Cyclone Yasi and its predecessors, northeast Queensland, Australia

[1] Four well-identified tropical cyclones over the past century have been responsible for depositing distinct units of predominantly quartzose sand and gravel to form the most seaward beach ridge at several locations along the wet tropical coast of northeast Queensland, Australia. These units deposited by tropical cyclones display a key sedimentary signature characterized by a sharp basal erosional contact, a coarser grain size than the underlying facies and a coarse-skewed trend toward the base. Coarse-skewed distributions with minimal change in mean grain size also characterize the upper levels of the high-energy deposited units at locations within the zone of maximum onshore winds during the tropical cyclone. These same coarse skew distributions are not apparent in sediments deposited at locations where predominantly offshore winds occurred during the cyclone, which in the case of northeast Australia is north of the eye-crossing location. These sedimentary signatures, along with the geochemical indicators and the degraded nature of the microfossil assemblages, have proven to be useful proxies to identify storm-deposited units within the study site and can also provide useful proxies in older beach ridges where advanced pedogenesis has obscured visual stratigraphic markers. As a consequence, more detailed long-term histories of storms and tropical cyclones can now be developed.

Skating on Olympic ice: working with winter Olympians

Working as a sport psychologist with Olympic athletes requires a clear understanding of a broad range of multifaceted individual, group, situational, and environmental issues, all of which have the ability to impact upon performance. This article provides an overview of some of the common yet vital issues that have been observed to arise when working with Olympic Winter Games athletes and teams; what to expect, how to recognise them when they occur, and why they are important to prepare for in the context of supporting athletes to achieve the best performance they can at an Olympic Games. Aimed at the emerging sport psychology practitioner, discussion of issues such as performing under pressure, dealing with distractions, adjusting to external factors, team culture, and servicing models creates an informal set of “practical guidelines” based upon real-world experiences that can also be applied to other major sporting competitions.

Estimating present day extreme water level exceedance probabilities around the coastline of Australia : tropical cyclone-induced storm surges

The incidence of major storm surges in the last decade have dramatically emphasized the immense destructive capabilities of extreme water level events, particularly when driven by severe tropical cyclones. Given this risk, it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood and erosion management, engineering and for future land-use planning and to ensure the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. Australia has a long history of coastal flooding from tropical cyclones. Using a novel integration of two modeling techniques, this paper provides the first estimates of present day extreme water level exceedance probabilities around the whole coastline of Australia, and the first estimates that combine the influence of astronomical tides, storm surges generated by both extra-tropical and tropical cyclones, and seasonal and inter-annual variations in mean sea level. Initially, an analysis of tide gauge records has been used to assess the characteristics of tropical cyclone-induced surges around Australia. However, given the dearth (temporal and spatial) of information around much of the coastline, and therefore the inability of these gauge records to adequately describe the regional climatology, an observationally based stochastic tropical cyclone model has been developed to synthetically extend the tropical cyclone record to 10,000 years. Wind and pressure fields derived for these synthetically generated events have then been used to drive a hydrodynamic model of the Australian continental shelf region with annual maximum water levels extracted to estimate exceedance probabilities around the coastline. To validate this methodology, selected historic storm surge events have been simulated and resultant storm surges compared with gauge records. Tropical cyclone induced exceedance probabilities have been combined with estimates derived from a 61-year water level hindcast described in a companion paper to give a single estimate of present day extreme water level probabilities around the whole coastline of Australia. Results of this work are freely available to coastal engineers, managers and researchers via a web-based tool (www.sealevelrise.info). The described methodology could be applied to other regions of the world, like the US east coast, that are subject to both extra-tropical and tropical cyclones.

Institutional response and Indigenous experiences of Cyclone Tracy

Early on Christmas morning 1974 Tropical Cyclone Tracy, a Category 4 storm, devastated the Northern Territory city of Darwin leaving only 6% of the city’s housing habitable. The extent of the disaster was largely the result of unregulated and poorly constructed buildings, predominantly housing. While the engineering and reconstruction process demonstrated a very successful response and adaptation to an existing and future risk, the impact of the cyclone of the local community and its Indigenous population in particular, had not been well recorded. NCCARF therefore commissioned a report on the Indigenous experience of Cyclone Tracy to document how Indigenous people were impacted by, responded to, and recovered from Cyclone Tracy in comparison to non-Indigenous groups. The report also considers the research literature on disasters and Indigenous people in the Northern Territory, with a specific focus on cyclones, and considers the socio-political context of Indigenous communities in Darwin prior to Cyclone Tracy.

Adaptation lessons from cyclone Tracy

This case study will review the impact of Tropical Cyclone Tracy on the city and people of Darwin, the Australian engineering and institutional responses that it invoked and the relevance of these lessons to a world threatened by global climate change. At Christmas, 1974, Tropical Cyclone Tracy laid waste the city of Darwin, an iconic episode in the history of Australian natural disasters. It provides one of the clearest and most successful examples worldwide of adaptation to a catastrophe. Following large losses in Townsville from Tropical Cyclone Althea in 1971, the level of destruction in Darwin was such that it led to new regulations mandating the use of the wind code for reconstruction, and eventually to similar regulations for new construction in other cyclone-prone areas of Australia.