6,527 research outputs found

    Evaluation of ERTS-1 data for certain hydrological uses

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    The author has identified the following significant results. ERTS-1 MSS data have been used in a variety of hydrologic research including snow-extent mapping; studies of snowmelt, snowmelt runoff, spectral reflectance of snow for assessing snowpack conditions, and snow albedo; lake ice formation, breakup, and migration; lake current measurements; multispectral studies of lake ice; and flood studies. MSS sensing of soil moisture over a well-vegetated test site was unsuccessfully attempted. Although a powerful research tool, ERTS-1 has very limited use as an operational system for hydrologic communities because of its 18-day revisit cycle and its lack of a quick look capability

    NOSS altimeter algorithm specifications

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    A description of all algorithms required for altimeter processing is given. Each description includes title, description, inputs/outputs, general algebraic sequences and data volume. All required input/output data files are described and the computer resources required for the entire altimeter processing system were estimated. The majority of the data processing requirements for any radar altimeter of the Seasat-1 type are scoped. Additions and deletions could be made for the specific altimeter products required by other projects

    Evaluation of LANDSAT-2 data for selected hydrologic applications

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    There are no author-identified significant results in this report

    Does the mode of delivery affect mathematics examination results?

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    At present most examinations are delivered on paper but there is a growing trend in many subjects to deliver some or part of these examinations by computer. It is therefore important to know whether there are any differences in the results obtained by candidates sitting examinations taken by computer compared with those obtained by candidates sitting conventional examinations using pen and paper. The purpose of this article is to describe the outcome of a pilot study designed to∗ investigate possible causes of any differences in results from the use of different modes of delivery in a mathematics examination. One outcome of this study was that the process of translating examination questions into a format required for use on the computer (but keeping this as a pen and paper test) can have a significant effect on examination results. However, the main conclusion is that changing the medium only has no effect on the results in mathematics examinations

    Evaluation of LANDSAT-2 data for selected hydrologic applications

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    There are no author-identified significant results in this report

    Time series semi-Markov decision process with variable costs for maintenance planning

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    Deciding when and how to maintain offshore wind turbines is becoming even more complex as the size of wind farms increases, while accessibility is challenging compared to onshore wind farms. Planning future maintenance actions requires the wind farm operator to consider factors such as the current condition of the turbine, the cost of a given maintenance action, revenue generated by the asset, weather factors and vessel availability. Rather than making case-by-case decisions for each turbine, the approach described in this paper allows the wind farm operators to automate the process of short to-medium term maintenance planning through application of a Semi-Markov Decision Process (SMDP). The model proposed here is capable of suggesting the cost-optimal maintenance policy given weather forecast, future vessel costs and availability and the current condition of the turbine. Using the semi-Markov approach, allows the user to implement time varying failure rate. As the model is capable of utilising time-series data, future weather and vessel constraints can be applied depending on the information available to the user at the time, which will be reflected in the optimal policy suggested by the model. The model proposed here facilitates maintenance decision making in wind farms and will lead to cost reduction through more efficient planning. In addition to that, the model can be used to carry out a cost-benefit analysis of using vessels with different properties

    Non-Universal Fractional Quantum Hall States in a Quantum wire

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    The ground state as well as low-lying excitations in a 2D electron system in strong magnetic fields and a parabolic potential is investigated by the variational Monte Calro method. Trial wave functions analogous to the Laughlin state are used with the power-law exponent as the variational parameter. Finite size scaling of the excitation energy shows that the correlation function at long distance is characterized by anon-universal exponent in sharp contrast to the standard Laughlin state.The Laughlin-type state becomes unstable depending on strength of the confining potential.Comment: 10 pages, REVTE

    Cancer and systemic inflammation: treat the tumour and treat the host

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    Determinants of cancer progression and survival are multifactorial and host responses are increasingly appreciated to have a major role. Indeed, the development and maintenance of a systemic inflammatory response has been consistently observed to confer poorer outcome, in both early and advanced stage disease. For patients, cancer-associated symptoms are of particular importance resulting in a marked impact on day-to-day quality of life and are also associated with poorer outcome. These symptoms are now recognised to cluster with one another with anorexia, weight loss and physical function forming a recognised cluster whereas fatigue, pain and depression forming another. Importantly, it has become apparent that these symptom clusters are associated with presence of a systemic inflammatory response in the patient with cancer. Given the understanding of the above, there is now a need to intervene to moderate systemic inflammatory responses, where present. In this context the rationale for therapeutic intervention using nonselective anti-inflammatory agents is clear and compelling and likely to become a part of routine clinical practice in the near future. The published literature on therapeutic intervention using anti-inflammatory agents for cancer-associated symptoms was reviewed. There are important parallels with the development of useful treatments for the systemic inflammatory response in patients with rheumatological disease and cardiovascular disease

    Two-Band-Type Superconducting Instability in MgB2

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    Using the tight-binding method for the π\pi-bands in MgB2_2, the Hubbard on-site Coulomb interaction on two inequivalent boron pzp_z-orbitals is transformed into expressions in terms of π\pi-band operators. For scattering processes relevant to the problemin which a wave vector {\bf q} is parallel to z^\hat{z}, it is found to take a relatively simple form consisting of intra-band Coulomb scattering, interband pair scattering etc. with large constant coupling constants. This allows to get a simple expression for the amplitude of interband pair scattering between two π\pi-bands, which diverges if the interband polarization function in it becomes large enough.The latter was approximately evaluated and found to be largely enhanced in the band structure in MgB2_2. These results lead to a divergent interband pair scattering, meaning two-band-type superconducting instability with enhanced TcT_c. Adding a subsidiary BCS attractive interaction in each band into consideration, a semi-quantitative gap equation is given, and TcT_c and isotope exponent α\alpha are derived. The present instability is asserted to be the origin of high TcT_c in MgB2_2.Comment: 4 pages, to be published in J. Phys. Soc. Jpn. vol. 70, No.
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