2,009 research outputs found

    Banda Aceh-The Value of Earth Observation Data in Disaster Recovery and Reconstruction: A Case Study

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    On 26 December 2004, Banda Aceh in Indonesia was at the center of one of the worst natural disasters to affect mankind. Large amounts of international aid poured in to assist in the relief and reconstruction efforts. Amongst this effort, were investments in basic earth observation data from in-situ, airborne and space observations. While the use of this data is assumed to be crucial, few efforts have gone into quantifying the benefits of its acquisition. The objectives of this study were to interview a cross-section of agencies operating in Banda Aceh and across the province of Nanggroe Aceh Darussalam on the use, sources and quality of earth observation data in the relief/reconstruction effort; and to analyze and quantify the value that earth observation data brings to the relief/reconstruction effort based on the survey results and specific examples. Key findings from the interviews point to an overall improvement in the spatial data situation since the tsunami. Problems identified included insufficient training, lack of timely data and sometimes poor spatial resolution. Specific examples of the cost-benefits of earth observation data were typically on the order of millions of dollars and involved large time savings. IIASA is one of 12 partners in the European Union sponsored project "Global Earth Observation/Benefit Estimation: Now, Next and Emerging" (GEO-BENE). Additional GEO-BENE partner countries include Germany, Switzerland, Slovakia, Netherlands, Finland, South Africa and Japan. Within GEO-BENE we are developing methodologies and analytical tools to assess societal benefits of GEO in nine societal benefit areas- one of which is disasters. The tsunami affected province of Nanggroe Aceh Darussalam, and specifically Banda Aceh, has been selected as a case study. Other case studies representing different societal benefit areas include: biodiversity in South Africa, health and climate in Finland, fire in Europe, etc. For more information please refer to: www.geo-bene.eu

    GEO Information For Disaster Recovery -- Case Study: The Use of Orthophotos in Aceh, Indonesia

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    This study, carried out between July-September 2008, looks specifically at the use of a high resolution aerial photograph (orthophoto) data set acquired in June 2005 over post tsunami Aceh, Indonesia. The study clearly demonstrates the benefit of the use of EO data for disaster recovery showing that the orthophoto data set, costing 1.4 million Euro, critically supported projects (primary users of the data set), worth over 16 times its actual cost (28 million Euro) and provided support to projects worth over 600 times its actual cost (880 million Euro). The study concludes that a simple robust methodology to quantify the benefit of EO data in disaster recovery may be implemented by monitoring the total costs of projects that are critically supported by the EO data set. To implement that monitoring mechanism, a robust and straightforward method must be in place with the EO data distributor that records simple criteria for each of the data users and related projects. The report provides a number of lessons that have been learnt from the spatial data initiatives between Official Development Agencies and the Government of Indonesia in response to the Tsunami. The report recommends that in order to ensure that the spatial data is used to its greatest benefit, prior to the initiation of any campaign, the donor funding the project must ensure that there is a defined and clearly proven, transparent, and accountable mechanism to ensure that the data is effectively delivered to the humanitarian aid community in a timely and efficient manner

    The arithmetic of hyperelliptic curves

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    We summarise recent advances in techniques for solving Diophantine problems on hyperelliptic curves; in particular, those for finding the rank of the Jacobian, and the set of rational points on the curve

    Phase transitions and iron-ordered moment form factor in LaFeAsO

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    Elastic neutron scattering studies of an optimized LaFeAsO single crystal reveal that upon cooling, an onset of the tetragonal (T)-to-orthorhombic (O) structural transition occurs at TS156T_\texttt{S} \approx 156 K, and it exhibits a sharp transition at TP148T_\texttt{P} \approx 148 K. We argue that in the temperature range TST_\texttt{S} to TPT_\texttt{P}, T and O structures may dynamically coexist possibly due to nematic spin correlations recently proposed for the iron pnictides, and we attribute TPT_\texttt{P} to the formation of long-range O domains from the finite local precursors. The antiferromagnetic structure emerges at TN140T_\texttt{N} \approx 140 K, with the iron moment direction along the O \emph{a} axis. We extract the iron magnetic form factor and use the tabulated j0\langle j_0\rangle of Fe, Fe2+^{2+} and Fe3+^{3+} to obtain a magnetic moment size of \sim0.8 μB\mu_\texttt{B} at 9.5 K.Comment: 7 pages, 6 figures, 3 table

    Digital support interventions for the self-management of low back pain: a systematic review

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    Background: Low back pain (LBP) is a common cause of disability and is ranked as the most burdensome health condition globally. Self-management, including components on increased knowledge, monitoring of symptoms, and physical activity, are consistently recommended in clinical guidelines as cost-effective strategies for LBP management and there is increasing interest in the potential role of digital health. Objective: The study aimed to synthesize and critically appraise published evidence concerning the use of interactive digital interventions to support self-management of LBP. The following specific questions were examined: (1) What are the key components of digital self-management interventions for LBP, including theoretical underpinnings? (2) What outcome measures have been used in randomized trials of digital self-management interventions in LBP and what effect, if any, did the intervention have on these? and (3) What specific characteristics or components, if any, of interventions appear to be associated with beneficial outcomes? Methods: Bibliographic databases searched from 2000 to March 2016 included Medline, Embase, CINAHL, PsycINFO, Cochrane Library, DoPHER and TRoPHI, Social Science Citation Index, and Science Citation Index. Reference and citation searching was also undertaken. Search strategy combined the following concepts: (1) back pain, (2) digital intervention, and (3) self-management. Only randomized controlled trial (RCT) protocols or completed RCTs involving adults with LBP published in peer-reviewed journals were included. Two reviewers independently screened titles and abstracts, full-text articles, extracted data, and assessed risk of bias using Cochrane risk of bias tool. An independent third reviewer adjudicated on disagreements. Data were synthesized narratively. Results: Of the total 7014 references identified, 11 were included, describing 9 studies: 6 completed RCTs and 3 protocols for future RCTs. The completed RCTs included a total of 2706 participants (range of 114-1343 participants per study) and varied considerably in the nature and delivery of the interventions, the duration/definition of LBP, the outcomes measured, and the effectiveness of the interventions. Participants were generally white, middle aged, and in 5 of 6 RCT reports, the majority were female and most reported educational level as time at college or higher. Only one study reported between-group differences in favor of the digital intervention. There was considerable variation in the extent of reporting the characteristics, components, and theories underpinning each intervention. None of the studies showed evidence of harm. Conclusions: The literature is extremely heterogeneous, making it difficult to understand what might work best, for whom, and in what circumstances. Participants were predominantly female, white, well educated, and middle aged, and thus the wider applicability of digital self-management interventions remains uncertain. No information on cost-effectiveness was reported. The evidence base for interactive digital interventions to support patient self-management of LBP remains weak

    S1×S2S^1 \times S^2 wormholes and topological charge

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    I investigate solutions to the Euclidean Einstein-matter field equations with topology S1×S2×RS^1 \times S^2 \times R in a theory with a massless periodic scalar field and electromagnetism. These solutions carry winding number of the periodic scalar as well as magnetic flux. They induce violations of a quasi-topological conservation law which conserves the product of magnetic flux and winding number on the background spacetime. I extend these solutions to a model with stable loops of superconducting cosmic string, and interpret them as contributing to the decay of such loops.Comment: 18 pages (includes 6 figs.), harvmac and epsf, CU-TP-62

    Community characterization of heterogeneous complex systems

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    We introduce an analytical statistical method to characterize the communities detected in heterogeneous complex systems. By posing a suitable null hypothesis, our method makes use of the hypergeometric distribution to assess the probability that a given property is over-expressed in the elements of a community with respect to all the elements of the investigated set. We apply our method to two specific complex networks, namely a network of world movies and a network of physics preprints. The characterization of the elements and of the communities is done in terms of languages and countries for the movie network and of journals and subject categories for papers. We find that our method is able to characterize clearly the identified communities. Moreover our method works well both for large and for small communities.Comment: 8 pages, 1 figure and 2 table

    Towards Physical Hybrid Systems

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    Some hybrid systems models are unsafe for mathematically correct but physically unrealistic reasons. For example, mathematical models can classify a system as being unsafe on a set that is too small to have physical importance. In particular, differences in measure zero sets in models of cyber-physical systems (CPS) have significant mathematical impact on the mathematical safety of these models even though differences on measure zero sets have no tangible physical effect in a real system. We develop the concept of "physical hybrid systems" (PHS) to help reunite mathematical models with physical reality. We modify a hybrid systems logic (differential temporal dynamic logic) by adding a first-class operator to elide distinctions on measure zero sets of time within CPS models. This approach facilitates modeling since it admits the verification of a wider class of models, including some physically realistic models that would otherwise be classified as mathematically unsafe. We also develop a proof calculus to help with the verification of PHS.Comment: CADE 201
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