751 research outputs found

    Private Outsourced Kriging Interpolation

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    Kriging is a spatial interpolation algorithm which provides the best unbiased linear prediction of an observed phenomena by taking a weighted average of samples within a neighbourhood. It is widely used in areas such as geo-statistics where, for example, it may be used to predict the quality of mineral deposits in a location based on previous sample measurements. Kriging has been identified as a good candidate process to be outsourced to a cloud service provider, though outsourcing presents an issue since measurements and predictions may be highly sensitive. We present a method for the private outsourcing of Kriging interpolation using a tailored modification of the Kriging algorithm in combination with homomorphic encryption, allowing crucial information relating to measurement values to be hidden from the cloud service provider

    Modelling the spatial distribution of DEM Error

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    Assessment of a DEM’s quality is usually undertaken by deriving a measure of DEM accuracy – how close the DEM’s elevation values are to the true elevation. Measures such as Root Mean Squared Error and standard deviation of the error are frequently used. These measures summarise elevation errors in a DEM as a single value. A more detailed description of DEM accuracy would allow better understanding of DEM quality and the consequent uncertainty associated with using DEMs in analytical applications. The research presented addresses the limitations of using a single root mean squared error (RMSE) value to represent the uncertainty associated with a DEM by developing a new technique for creating a spatially distributed model of DEM quality – an accuracy surface. The technique is based on the hypothesis that the distribution and scale of elevation error within a DEM are at least partly related to morphometric characteristics of the terrain. The technique involves generating a set of terrain parameters to characterise terrain morphometry and developing regression models to define the relationship between DEM error and morphometric character. The regression models form the basis for creating standard deviation surfaces to represent DEM accuracy. The hypothesis is shown to be true and reliable accuracy surfaces are successfully created. These accuracy surfaces provide more detailed information about DEM accuracy than a single global estimate of RMSE

    Experiences of Using Pathways and Resources for Participation and Engagement (PREP) Intervention for Children with Acquired Brain Injury: A Knowledge Translation Study.

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    Children with acquired brain injury experience participation restrictions. Pathways and Resources for Participation and Engagement (PREP) is an innovative, participation focused intervention. Studies have examined PREP in Canadian research contexts, however little is known about implementation in real-life clinical settings. This study aimed to understand experiences of clinicians implementing PREP in a UK clinical context, with a focus on implementation processes and key factors for successful implementation. A qualitative single-site 8-week knowledge translation intervention study, guided by an action research framework, explored clinicians' experiences of implementation. Six occupational therapists (OTs) working in a neurorehabilitation setting participated. The therapists provided two intervention sessions per week, over four weeks for one child on their caseload. Planning, implementation and evaluation were explored through two focus groups. Thematic analysis was used to analyse data. Two themes, "key ingredients before you start" and "PREP guides the journey", were identified before introducing PREP to practice. Four additional themes were related to PREP implementation: "shifting to a participation perspective", "participation moves beyond the OT", "environmental challengers and remedies" and "whole family readiness". A participation ripple effect was observed by building capacity across the multi-disciplinary team and families. The involvement of peers, social opportunities and acknowledging family readiness were key factors for successful implementation. The findings illustrate practical guidance to facilitate the uptake of participation-based evidence in clinical practice. Further research is required to understand aspects of knowledge translation when implementing participation interventions in other UK clinical settings

    Geospatial information infrastructures

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    Manual of Digital Earth / Editors: Huadong Guo, Michael F. Goodchild, Alessandro Annoni .- Springer, 2020 .- ISBN: 978-981-32-9915-3Geospatial information infrastructures (GIIs) provide the technological, semantic,organizationalandlegalstructurethatallowforthediscovery,sharing,and use of geospatial information (GI). In this chapter, we introduce the overall concept and surrounding notions such as geographic information systems (GIS) and spatial datainfrastructures(SDI).WeoutlinethehistoryofGIIsintermsoftheorganizational andtechnologicaldevelopmentsaswellasthecurrentstate-of-art,andreflectonsome of the central challenges and possible future trajectories. We focus on the tension betweenincreasedneedsforstandardizationandtheever-acceleratingtechnological changes. We conclude that GIIs evolved as a strong underpinning contribution to implementation of the Digital Earth vision. In the future, these infrastructures are challengedtobecomeflexibleandrobustenoughtoabsorbandembracetechnological transformationsandtheaccompanyingsocietalandorganizationalimplications.With this contribution, we present the reader a comprehensive overview of the field and a solid basis for reflections about future developments

    A Survey of Volunteered Open Geo-Knowledge Bases in the Semantic Web

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    Over the past decade, rapid advances in web technologies, coupled with innovative models of spatial data collection and consumption, have generated a robust growth in geo-referenced information, resulting in spatial information overload. Increasing 'geographic intelligence' in traditional text-based information retrieval has become a prominent approach to respond to this issue and to fulfill users' spatial information needs. Numerous efforts in the Semantic Geospatial Web, Volunteered Geographic Information (VGI), and the Linking Open Data initiative have converged in a constellation of open knowledge bases, freely available online. In this article, we survey these open knowledge bases, focusing on their geospatial dimension. Particular attention is devoted to the crucial issue of the quality of geo-knowledge bases, as well as of crowdsourced data. A new knowledge base, the OpenStreetMap Semantic Network, is outlined as our contribution to this area. Research directions in information integration and Geographic Information Retrieval (GIR) are then reviewed, with a critical discussion of their current limitations and future prospects

    An adverbial approach for the formal specification of topological constraints involving regions with broad boundaries

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    Topological integrity constraints control the topological properties of spatial objects and the validity of their topological relationships in spatial databases. These constraints can be specified by using formal languages such as the spatial extension of the Object Constraint Language (OCL). Spatial OCL allows the expression of topological constraints involving crisp spatial objects. However, topological constraints involving spatial objects with vague shapes (e.g., regions with broad boundaries) are not supported by this language. Shape vagueness requires using appropriate topological operators (e.g., strongly Disjoint, fairly Meet) to specify valid relations between these objects; otherwise, the constraints cannot be respected. This paper addresses the problem of the lack of terminology to express topological constraints involving regions with broad boundaries. We propose an extension of Spatial OCL based on a geometric model for objects with vague shapes and an adverbial approach for topological relations between regions with broad boundaries. This extension of Spatial OCL is then tested on an agricultural database

    Reproducibility of the cytokine response following nasal allergen challenge

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    Reproducibility of the Cytokine Response Following Nasal Allergen ChallengeCT Pantin, J Burrough, P Cadden, D SinghUniversity of Manchester, Medicines Evaluation Unit, University Hospital of South Manchester Foundation Trust, Southmoor Road, ManchesterRationale: Nasally inhaled allergen provokes increased nasal secretion, cytokine production, and nasal symptoms. This induces a biphasic allergic response comprising of an early (0-2hours) and a late component (4-8 hours). The aim of this study is to investigate the reproducibility of late response cytokine levels in secretions post nasal allergen challenge.Methods: 17 subjects with allergic rhinitis underwent nasal allegen challenge. Skin prick testing was performed to determine the choice of allergen (which comprised cat, house dust mite and 6 species of grass) utilized to challenge study subjects. Nasal secretions (collected by Ivalon® Post-op Sinus Pack K9), nasal secretion weight and total nasal symptom score were measured from baseline up to 8 hours post allergen inhalation. A repeat nasal allergen challenge was performed 7 to 14 days later. Concentrations of IL-5 and IL-8 in the post allergen challenge nasal secretions were determined using ELISA and corrected for nasal secretion weight to give the absolute cytokine concentration per subject. The 8 hour time point was analysed for reproducibility.Results: IL-5 concentrations were elevated from 4 hours through to 8 hours post allergen challenge at both visits in 7 subjects’ nasal secretions. No IL-5 was detected at any time point in 10 subjects. There was no significant difference in the 8 hour IL-5 concentration between visits (p=0.38). IL-8 concentrations increased from 4 hours through to 8 hours post allergen at both visits in all subjects. There was no significant difference in IL-8 concentration between visits (p=0.86). The intra class correlation coefficient (ri) for both cytokines was > 0.6 suggesting good agreement between the two challenges. The ri value for IL-8 is > 0.75 indicating very good agreement.Cytokine (pg) First Nasal Allergen ChallengeMean (SD) Second Nasal Allergen ChallengeMean (SD) Mean Difference(95% CI) Intra Class Correlation CoefficientIL-5 62.2 (82.8) 185.5 (224.9) 123.3 (-40.8, 287.4) 0.62 IL-8 262.0 (300.2) 322.3 (394.5) 60.3 (-175.5, 296.1) 0.76 Table Reproducibility of Cytokine Response at 8 Hours Following Nasal Allergen ChallengeConclusions: Nasal allergen challenges using Ivalon® Post-op Sinus Pack K9 sponges are able to reproducibly detect the nasal late allergen cytokine response

    Rethinking the learning space at work and beyond: The achievement of agency across the boundaries of work-related spaces and environments

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    This paper focuses on the notion of the learning space at work and discusses the extent to which its different configurations allow employees to exercise personal agency within a range of learning spaces. Although the learning space at work is already the subject of extensive research, the continuous development of the learning society and the development of new types of working spaces calls for further research to advance our knowledge and understanding of the ways that individuals exercise agency and learn in the workplace. Research findings suggest that the current perception of workplace learning is strongly related to the notion of the learning space, in which individuals and teams work, learn and develop their skills. The perception of the workplace as a site only for work-specific training is gradually changing, as workplaces are now acknowledged as sites for learning in various configurations, and as contributing to the personal development and social engagement of employees. This paper argues that personal agency is constructed in the workplace, and this process involves active interrelations between agency and three dimensions of the workplace (individual, spatial and organisational), identified through both empirical and theoretical research. The discussion is supported by data from two research projects on workplace learning in the United Kingdom. This paper thus considers how different configurations of the learning space and the boundaries between a range of work-related spaces facilitate the achievement of personal agency

    Monthly precipitation mapping of the Iberian Peninsula using spatial interpolation tools implemented in a Geographic Information System

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    Premi a l'excel·lència investigadora. Àmbit de les Ciències Socials. 2008In this study, spatial interpolation techniques have been applied to develop an objective climatic cartography of precipitation in the Iberian Peninsula (583,551 km2). The resulting maps have a 200m spatial resolution and a monthly temporal resolution. Multiple regression, combined with a residual correction method, has been used to interpolate the observed data collected from the meteorological stations. This method is attractive as it takes into account geographic information (independent variables) to interpolate the climatic data (dependent variable). Several models have been developed using different independent variables, applying several interpolation techniques and grouping the observed data into different subsets (drainage basin models) or into a single set (global model). Each map is provided with its associated accuracy, which is obtained through a simple regression between independent observed data and predicted values. This validation has shown that the most accurate results are obtained when using the global model with multiple regression mixed with the splines interpolation of the residuals. In this optimum case, the average R2 (mean of all the months) is 0.85. The entire process has been implemented in a GIS (Geographic Information System) which has greatly facilitated the filtering, querying, mapping and distributing of the final cartography

    The spatial structure of lithic landscapes : the late holocene record of east-central Argentina as a case study

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    Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Catella, Luciana. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Oliva, Fernando. Centro Estudios Arqueológicos Regionales. Facultad de Humanidades y Artes. Universidad Nacional de Rosario; Argentin
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