797 research outputs found
Fusion of monocular cues to detect man-made structures in aerial imagery
The extraction of buildings from aerial imagery is a complex problem for automated computer vision. It requires locating regions in a scene that possess properties distinguishing them as man-made objects as opposed to naturally occurring terrain features. It is reasonable to assume that no single detection method can correctly delineate or verify buildings in every scene. A cooperative-methods paradigm is useful in approaching the building extraction problem. Using this paradigm, each extraction technique provides information which can be added or assimilated into an overall interpretation of the scene. Thus, the main objective is to explore the development of computer vision system that integrates the results of various scene analysis techniques into an accurate and robust interpretation of the underlying three dimensional scene. The problem of building hypothesis fusion in aerial imagery is discussed. Building extraction techniques are briefly surveyed, including four building extraction, verification, and clustering systems. A method for fusing the symbolic data generated by these systems is described, and applied to monocular image and stereo image data sets. Evaluation methods for the fusion results are described, and the fusion results are analyzed using these methods
Patient experiences of an ankle fracture and the most important factors in their recovery : a qualitative interview study
Objective The objective of this qualitative research study is to explore patient experiences of ankle fracture and the factors most important to them in recovery.
Design Semistructured interviews exploring patient experiences of ankle fracture recovery at 16ā23 weeks following injury. Interviews followed a topic guide and were recorded with an encrypted audio recorder and then transcribed verbatim. Thematic content analysis was used to identify themes in the data.
Setting Individuals were recruited from a sample of participants of a UK-based clinical trial of immobilisation methods for ankle fracture (ISRCTN15537280 at the pre-results stage at time of writing). Interviews were conducted at the participantsā own homes or on a university campus setting.
Participants A purposive sample was used to account for key variables of age, gender and fracture management. Participants recruited from the clinical trial sample were adults aged 18 years or over with a closed ankle fracture.
Results Ten participants were interviewed, five of whom were female and six of whom needed an operation to fix their ankle fracture. The age range of participants was 21ā75 years with a mean of 51.6 years. Eight themes emerged from the data during analysis; mobility, loss of independence, healthcare, psychological effects, social and family life, ankle symptoms, sleep disturbance and fatigue, and activities of daily living. Factors of importance to participants included regaining their independence, sleep quality and quantity, ability to drive, ability to walk without walking aids or weight-bearing restrictions, and radiological union.
Conclusions The results of this research demonstrates the extensive impact of ankle fracture on individualsā lives, including social and family life, sleep, their sense of independence and psychological well-being. The results of this study will enable an increased understanding of the factors of relevance to individuals with ankle fracture, allowing collection of appropriate outcomes in clinical studies for this condition. Ultimately these results will help formulate appropriate patient-centred rehabilitation plans for these patients
High-speed, in-band performance measurement instrumentation for next generation IP networks
Facilitating always-on instrumentation of Internet traffic for the purposes of performance measurement is crucial in order to enable accountability of resource usage and automated network control, management and optimisation. This has proven infeasible to date due to the lack of native measurement mechanisms that can form an integral part of the networkās main forwarding operation. However, Internet Protocol version 6 (IPv6) specification enables the efficient encoding and processing of optional per-packet information as a native part of the network layer, and this constitutes a strong reason for IPv6 to be adopted as the ubiquitous next generation Internet transport.
In this paper we present a very high-speed hardware implementation of in-line measurement, a truly native traffic instrumentation mechanism for the next generation Internet, which facilitates performance measurement of the actual data-carrying traffic at small timescales between two points in the network. This system is designed to operate as part of the routers' fast path and to incur an absolutely minimal impact on the network operation even while instrumenting traffic between the edges of very high capacity links. Our results show that the implementation can be easily accommodated by current FPGA technology, and real Internet traffic traces verify that the overhead incurred by instrumenting every packet over a 10 Gb/s operational backbone link carrying a typical workload is indeed negligible
Extending and Evaluating a Platform for Story Understanding
We summarize recent developments in our platform for symbolically representing and reasoning over human narratives. The expressive range of the system is bolstered by the infusion of a large library of knowledge frames, including verbs, adjectives, nouns and adverbs,
from external linguistic resources. Extensions to the model itself include alternate timelines (imagined states for goals, plans, beliefs and other modalities), hypotheticals, modiļ¬ers and connections between instantiated frames such as causality. We describe a corpus collection experiment that evaluates the usability of the graphical encoding interface, and measure the inter-annotator agreement yielded by our novel representation and tool
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Identifying similarities and differences across English and Arabic news
We present a new approach for summarizing topically clustered documents from two sources, English and machine translated Arabic texts, that presents users with an overview of the differences in content of the two sources, and information that is supported by both sources. Our approach to multilingual multi-document summarization clusters all input document sentences, and identifies sentence clusters that contain information exclusive to the Arabic documents, information exclusive to the English documents, and information that is similar between the two. The result is a three-part summary describing information about the event that comes exclusively from Arabic sources, information coming exclusively from English sources, and information that both sources consider important, enabling analysts to more quickly understand differences between incoming documents from different sources. We report on a user evaluation of the summaries
Effect of induction agent on vasopressor and steroid use, and outcome in patients with septic shock
Optimal L\'{e}vy-flight foraging in a finite landscape
We present a simple model to study L\'{e}vy-flight foraging in a finite
landscape with countable targets. In our approach, foraging is a step-based
exploratory random search process with a power-law step-size distribution . We find that, when the termination is regulated by a finite
number of steps , the optimum value of that maximises the foraging
efficiency can vary substantially in the interval , depending on
the landscape features (landscape size and number of targets). We further
demonstrate that subjective returning can be another significant factor that
affects the foraging efficiency in such context. Our results suggest that
L\'{e}vy-flight foraging may arise through an interaction between the
environmental context and the termination of exploitation, and particularly
that the number of steps can play an important role in this scenario which is
overlooked by most previous work. Our study not only provides a new perspective
on L\'{e}vy-flight foraging, but also opens new avenues for investigating the
interaction between foraging dynamics and environment as well as offers a
realistic framework for analysing animal movement patterns from empirical data.Comment: 25 pages, 6 figure
Analysis and clinical findings of cases positive for the novel synthetic cannabinoid receptor agonist MDMB-CHMICA
Context: MDMB-CHMICA is a synthetic cannabinoid receptor agonist which has caused concern due to its presence in cases of adverse reaction and death. Method: 43 cases of suspected synthetic cannabinoid ingestion were identified from patients presenting at an Emergency Department and from post-mortem casework. These were subjected to liquid-liquid extraction using tertiary-butyl methyl ether and quantitatively analysed by Electospray Ionisation Liquid Chromatography ā tandem Mass Spectrometry. For positive samples, case and clinical details were sought and interrogated. Results: 11 samples were found positive for MDMB-CHMICA. Concentrations found ranged from <1 ā 22 ng/mL (mean: 6 ng/mL, median: 3 ng/mL). The age range was 15 ā 44 years (mean: 26 years, median: 21 years), with the majority (82%) of positive results found in males. Clinical presentations included hypothermia, hypoglycaemia, syncope, recurrent vomiting, altered mental state and serotonin toxicity, with corresponding concentrations of MDMB-CHMICA as low as <1 ng/mL. Duration of hospitalisation ranged from 3 ā 24 hours (mean: 12 hours, median: 8 hours). Discussion: The concentration range presented in this case series is indicative of MDMB-CHMICA having a high potency, as is known to be the case for other synthetic cannabinoid receptor agonists. The age range and gender representation were consistent with that reported for users of other drugs of this type. The clinical presentations observed were typical of synthetic cannabinoid receptor agonists and show the difficulties in identifying reactions potentially associated with drugs of this type. Conclusion: The range of MDMB-CHMICA concentrations in Emergency Department presentations (n=9) and post-mortem cases (n=2) was reported. No correlation between the concentration of this drug and clinical presentation or cause of death was reported in this sample. However, the potential for harm associated with low concentrations of MDMB-CHMICA and the
symptoms of toxicity being non-specific was highlighted
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