43 research outputs found

    Detecting modification of biomedical events using a deep parsing approach

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    <p>Abstract</p> <p>Background</p> <p>This work describes a system for identifying event mentions in bio-molecular research abstracts that are either speculative (e.g. <it>analysis of IkappaBalpha phosphorylation</it>, where it is not specified whether phosphorylation did or did not occur) or negated (e.g. <it>inhibition of IkappaBalpha phosphorylation</it>, where phosphorylation did <it>not </it>occur). The data comes from a standard dataset created for the BioNLP 2009 Shared Task. The system uses a machine-learning approach, where the features used for classification are a combination of shallow features derived from the words of the sentences and more complex features based on the semantic outputs produced by a deep parser.</p> <p>Method</p> <p>To detect event modification, we use a Maximum Entropy learner with features extracted from the data relative to the trigger words of the events. The shallow features are bag-of-words features based on a small sliding context window of 3-4 tokens on either side of the trigger word. The deep parser features are derived from parses produced by the English Resource Grammar and the <it>RASP </it>parser. The outputs of these parsers are converted into the Minimal Recursion Semantics formalism, and from this, we extract features motivated by linguistics and the data itself. All of these features are combined to create training or test data for the machine learning algorithm.</p> <p>Results</p> <p>Over the test data, our methods produce approximately a 4% absolute increase in F-score for detection of event modification compared to a baseline based only on the shallow bag-of-words features.</p> <p>Conclusions</p> <p>Our results indicate that grammar-based techniques can enhance the accuracy of methods for detecting event modification.</p

    Early warning of systemic risk in global banking: eigen-pair R number for financial contagion and market price-based methods

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    We analyse systemic risk in the core global banking system using a new network-based spectral eigen-pair method, which treats network failure as a dynamical system stability problem. This is compared with market price-based Systemic Risk Indexes, viz. Marginal Expected Shortfall, Delta Conditional Value-at-Risk, and Conditional Capital Shortfall Measure of Systemic Risk in a cross-border setting. Unlike paradoxical market price based risk measures, which underestimate risk during periods of asset price booms, the eigen-pair method based on bilateral balance sheet data gives early-warning of instability in terms of the tipping point that is analogous to the R number in epidemic models. For this regulatory capital thresholds are used. Furthermore, network centrality measures identify systemically important and vulnerable banking systems. Market price-based SRIs are contemporaneous with the crisis and they are found to covary with risk measures like VaR and betas

    Surface Glyphs for Efficient Visualization of Spatial Multivariate Data

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    New method to evaluate the practice of positive pressure ventilation in intensive care units.

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    BACKGROUND: There is good evidence to support the use of a "protective" ventilation strategy, using small tidal volumes and inspiratory pressures, in patients with acute respiratory distress syndrome. Many general intensive care units in the UK are being slow to adopt this approach and we therefore set out to devise a method to audit ventilation and possibly influence practice in these units. METHODS: Using variables that are routinely documented by intensive care nurses, we assessed the relationship between ventilator settings and arterial blood gas values on 30 consecutive ventilated patients admitted to intensive care units at both a teaching and a district hospital. Data were recorded twice daily and the proportions of data points where there was unnecessary hyperventilation were recorded at each centre. RESULTS: The initial audit results showed clear differences in practice between the teaching hospital and the district hospital. After an intensive education programme, during which an active role for nursing staff in ventilator management was encouraged, supported by simple protocols, practice in the district hospital was re-audited and found to closely mirror that in the teaching centre. CONCLUSIONS: To assist progress towards the use of a "protective" ventilation strategy in intensive care units in the UK, we devised a simple, robust audit method. We have shown how this method can give a more uniform practice of ventilation in critical care units, with the introduction of nurse-run protocols

    Physically-Based Interactive Camera Motion Control Using 3d Input Devices

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    The newest three-dimensional input devices, together with high speed graphics workstations, make it possible to interactively specify virtual camera motions for animation in real time. In this paper, we describe how naturalistic interaction and realistic-looking motion can be achieved by using a physicallybased model of the camera&apos;s behavior. Our approach is to create an abstract physical model of the camera, using the laws of classical mechanics, which is used to simulate the virtual camera motion in real time in response to force data from the various 3D input devices (e.g. the Spaceball, Polhemus and DataGlove). The behavior of the model is determined by several physical parameters such as mass, moment of inertia, and various friction coefficients which can all be varied interactively, and by constraints on the camera&apos;s degrees of freedom which can be simulated by setting certain friction parameters to very high values. This allows us to explore a continuous range of physically-base..

    Virtual Construction: Interactive Tools for Collaboration in Virtual Reality

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    Virtual technologies and game engines provide new possibilities for collaborative virtual design within digital building models. The current paper describes an approach, in which computer-aided design (CAD) models of buildings are transferred into a game engine based environment, where they can be reviewed and further designed collaboratively. Following a user-centered design (UCD) process based on interviews and iterative interactions with designers and architects, the prototype of Virtual Construction─a game engine based platform for collaborative virtual design meetings─was designed and implemented using Unreal Engine 4. The interactive tools developed can be used both in full immersive virtual reality and using traditional devices (e.g. laptop or desktop computers). Based on identified user needs, interaction techniques were implemented for moving, rotating, and aligning objects, adding and resizing shapes and objects, as well as moving and measuring distances in the three-dimensional (3D) building model. In addition, the communication techniques implemented based on user needs included synchronous features such as voice communication, text chat, pointing, and drawing, and asynchronous features such as leaving messages and feedback augmented with screenshots to exact virtual locations. Other implemented scenarios included different lighting scenarios, an evacuation scenario and crowdsourced voting between different designs.acceptedVersionPeer reviewe

    Time-based and event-based prospective memory in autism spectrum disorder: The roles of executive function, theory of mind, and time-estimation

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    Prospective memory (remembering to carry out an action in the future) has been studied relatively little in ASD. We explored time-based (carry out an action at a pre-specified time) and event-based (carry out an action upon the occurrence of a pre-specified event) prospective memory, as well as possible cognitive correlates, among 21 intellectually high-functioning children with ASD, and 21 age- and IQ-matched neurotypical comparison children. We found impaired time-based, but undiminished event-based, prospective memory among children with ASD. In the ASD group, time-based prospective memory performance was associated significantly with diminished theory of mind, but not with diminished cognitive flexibility. There was no evidence that time-estimation ability contributed to time-based prospective memory impairment in ASD
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