15 research outputs found

    The 'Paris-end' of town? Urban typology through machine learning

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    The confluence of recent advances in availability of geospatial information, computing power, and artificial intelligence offers new opportunities to understand how and where our cities differ or are alike. Departing from a traditional `top-down' analysis of urban design features, this project analyses millions of images of urban form (consisting of street view, satellite imagery, and street maps) to find shared characteristics. A (novel) neural network-based framework is trained with imagery from the largest 1692 cities in the world and the resulting models are used to compare within-city locations from Melbourne and Sydney to determine the closest connections between these areas and their international comparators. This work demonstrates a new, consistent, and objective method to begin to understand the relationship between cities and their health, transport, and environmental consequences of their design. The results show specific advantages and disadvantages using each type of imagery. Neural networks trained with map imagery will be highly influenced by the mix of roads, public transport, and green and blue space as well as the structure of these elements. The colours of natural and built features stand out as dominant characteristics in satellite imagery. The use of street view imagery will emphasise the features of a human scaled visual geography of streetscapes. Finally, and perhaps most importantly, this research also answers the age-old question, ``Is there really a `Paris-end' to your city?''

    Identifying safe intersection design through unsupervised feature extraction from satellite imagery

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    The World Health Organization has listed the design of safer intersections as a key intervention to reduce global road trauma. This article presents the first study to systematically analyze the design of all intersections in a large country, based on aerial imagery and deep learning. Approximately 900,000 satellite images were downloaded for all intersections in Australia and customized computer vision techniques emphasized the road infrastructure. A deep autoencoder extracted high-level features, including the intersection's type, size, shape, lane markings, and complexity, which were used to cluster similar designs. An Australian telematics data set linked infrastructure design to driving behaviors captured during 66 million kilometers of driving. This showed more frequent hard acceleration events (per vehicle) at four- than three-way intersections, relatively low hard deceleration frequencies at T-intersections, and consistently low average speeds on roundabouts. Overall, domain-specific feature extraction enabled the identification of infrastructure improvements that could result in safer driving behaviors, potentially reducing road trauma.Comment: 16 pages, 10 figures. Computer-Aided Civil and Infrastructure Engineering (2020

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    A new Cross Band Transformer (CBT) architecture for pansharpening of satellite imagery

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    Sev2Mod dataset has been constructed by utilizing two separate instruments on board of different satellites. Importantly, both instruments operated at different spatial resolutions. Low-resolution imagery was obtained from a geostationary satellite, providing measurements every five minutes. In contrast, high-resolution imagery was obtained from a sun-synchronous polar orbiting satellite which is available only twice a day. Sev2Mod represents the task of increasing image resolution while main- taining data availability, producing high-resolution geostationary images on a quasi-continuous basis. In detail, input pairs were collected from the Spinning Enhanced Visible and InfraRed Imager () (SEVIRI) on- board the geostationary MSG satellite, positioned at the equator at 9.5◦ East. Specifically, SEVIRI bands VIS006 (measuring around 0.6 μm) and VIS008 (measuring around0.8 μm) served as LRMS data, while SEVIRI band HRVIS (measuring between 0.6 and 0.9 μm) provided PAN data. Output pairs were collected from the Moderate Resolution Imaging Spectroradiometer (cite (MODIS) onboard the polar orbiting EOS-Terra satellite. MODIS bands 1 and 2 served as HRMS counterparts, operating in a similar spectral range as the SEVIRI VIS006 and VIS008 bands, re- spectively. Over southern Europe and northern Africa, our study area, the ground sampling distance of the SEVIRI LRMS and PAN images is around 3 × 3 and 1 × 1 km, respectively. The sampling distance of the MODIS HRMS images is 250 × 250 m. To construct the Sev2Mod dataset, image pairs taken from the same area and approximately the same time (± 30 seconds) and area were collected from both satellite instruments. MODIS images were resampled using Satpy [41] to spatially overlap with the SEVIRI grid while their native spatial resolution was approximately con- served. Subsequently, the generated tiles were cropped by a sliding window with small overlap. The resulted dimension are 16×16 pixels for LRMS, 48×48 for PAN and 192×192 for HRMS. Hence, the dataset resulted in a ×12 increase in resolution in each direction between the input and target images. Because SEVIRI and MODIS make observations with different viewing angles, spectral channels and slightly different acquisition times, and because their respective cal- ibrations and noise levels are not identical, Sev2Mod includes inconsistencies between source and target images which one might typically encounter in advanced pansharpening applications. Hence, the performance on this dataset is more indicative of real-world performance than artificially downscaled benchmark

    The effects of feedback and incentive-based insurance on driving behaviours:Study approach and protocols

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    BACKGROUND: Road injury is the leading cause of death for young people, with human error a contributing factor in many crash events. This research is the first experimental study to examine the extent to which direct feedback and incentive-based insurance modifies a driver's behaviour. The study applies in-vehicle telematics and will link the information obtained from the technology directly to personalised safety messaging and personal injury and property damage insurance premiums. METHODS: The study has two stages. The first stage involves laboratory experiments using a state-of-the-art driving simulator. These experiments will test the effects of various monetary incentives on unsafe driving behaviours. The second stage builds on these experiments and involves a randomised control trial to test the effects of both direct feedback (safety messaging) and monetary incentives on driving behaviour. DISCUSSION: Assuming a positive finding associated with the monetary incentive-based approach, the study will dramatically influence the personal injury and property damage insurance industry. In addition, the findings will also illustrate the role that in-vehicle telematics can play in providing direct feedback to young/novice drivers in relation to their driving behaviours which has the potential to transform road safety
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