16,123 research outputs found

    Coastal subsidence in Oregon, USA, during the Giant Cascadia earthquake of AD 1700

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    Quantitative estimates of land-level change during the giant AD 1700 Cascadia earthquake along the Oregon coast are inferred from relative sea-level changes reconstructed from fossil foraminiferal assemblages preserved within the stratigraphic record. A transfer function, based upon a regional training set of modern sediment samples from Oregon estuaries, is calibrated to fossil assemblages in sequences of samples across buried peat-mud and peat-sand contacts marking the AD 1700 earthquake. Reconstructions of sample elevations with sample-specific errors estimate the amount of coastal subsidence during the earthquake at six sites along 400 km of coast. The elevation estimates are supported by lithological, carbon isotope, and faunal tidal zonation data. Coseismic subsidence at Nehalem River, Nestucca River, Salmon River, Alsea Bay, Siuslaw River and South Slough varies between 0.18 m and 0.85 m with errors between 0.18 m and 0.32 m. These subsidence estimates are more precise, consistent, and generally lower than previous semi-quantitative estimates. Following earlier comparisons of semi-quantitative subsidence estimates with elastic dislocation models of megathrust rupture during great earthquakes, our lower estimates for central and northern Oregon are consistent with modeled rates of strain accumulation and amounts of slip on the subduction megathrust, and thus, with a magnitude of 9 for the AD 1700 earthquake

    Integrating dark and light biohydrogen production strategies: towards the hydrogen economy

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    Biological methods of hydrogen production are preferable to chemical methods because of the possibility to use sunlight, CO2 and organic wastes as substrates for environmentally benign conversions, under moderate conditions. By combining different microorganisms with different capabilities, the individual strengths of each may be exploited and their weaknesses overcome. Mechanisms of bio-hydrogen production are described and strategies for their integration are discussed. Dual systems can be\ud divided broadly into wholly light-driven systems (with microalgae/cyanobacteria as the 1st stage) and partially light-driven systems (with a dark, fermentative initial reaction). Review and evaluation of published data suggests that the latter type of system holds greater promise for industrial application. This is because the calculated land area required for a wholly light-driven dual system would be too large for either centralised (macro-) or decentralised(micro-) energy generation. The potential contribution to the hydrogen economy of partially light-driven dual systems is overviewed alongside that of other biofuels such as bio-methane and bio-ethanol

    Latent Self-Exciting Point Process Model for Spatial-Temporal Networks

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    We propose a latent self-exciting point process model that describes geographically distributed interactions between pairs of entities. In contrast to most existing approaches that assume fully observable interactions, here we consider a scenario where certain interaction events lack information about participants. Instead, this information needs to be inferred from the available observations. We develop an efficient approximate algorithm based on variational expectation-maximization to infer unknown participants in an event given the location and the time of the event. We validate the model on synthetic as well as real-world data, and obtain very promising results on the identity-inference task. We also use our model to predict the timing and participants of future events, and demonstrate that it compares favorably with baseline approaches.Comment: 20 pages, 6 figures (v3); 11 pages, 6 figures (v2); previous version appeared in the 9th Bayesian Modeling Applications Workshop, UAI'1

    Resource consents - intangible fixed assets? Yes, but, too difficult by far!

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    Recent international attempts to draft an accounting standard (IAS38) which establishes the most widely acceptable treatment for intangible assets have sparked debate among standard setters, practising accountants and media analysts. Contentious issues include differing treatment for internally and externally generated intangible fixed assets, and the requirement for the existence of a ready market for the exchange of intangible assets. A further question has been identified, that of whether the ‘right to do something’, as in permission to act, is in itself an intangible asset and if so how should it be treated. An example of this is resource consents issued under the Resource Management Act 1991. The aim of this research was to investigate the nature of resource consents as intangible assets according to ICANZ disclosure and recognition standards and to determine the level of disclosure practised by companies listed on the New Zealand Stock Exchange. Disclosure of resource consent details as non-financial information would provide a significant proportion of the benefits involved in disclosing this class of asset while limiting the costs involved in the production of the information. We conclude that the details of resource consents held should be disclosed in the annual report as additional non-financial information, or as a separate schedule of resource consents held in the notes to the financial statements as per FRS1. This view is not addressed by the requirements of IAS38 or ED87 as this 'class of intangible assets' is not discussed at all. However, it can be argued that the omission of resource consents and other similar intangibles is contrary to the spirit of the true and fair view requirement of the Financial Reporting Act and Generally Accepted Accounting Principles (GAAP)

    PUCM Practice Development Programme (PDP): February 2005

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    The purpose of this report is to identify a Practice Development Programme (PDP) for the presentation of relevant innovative practices and tools arising out of the first two Phases of PUCM (Planning Under Co-operative Mandates). During Phase 3 of the research (2004-2006) the PDP will be extended as new findings come to hand
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