94,292 research outputs found

    SAMP, the Simple Application Messaging Protocol: Letting applications talk to each other

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    SAMP, the Simple Application Messaging Protocol, is a hub-based communication standard for the exchange of data and control between participating client applications. It has been developed within the context of the Virtual Observatory with the aim of enabling specialised data analysis tools to cooperate as a loosely integrated suite, and is now in use by many and varied desktop and web-based applications dealing with astronomical data. This paper reviews the requirements and design principles that led to SAMP's specification, provides a high-level description of the protocol, and discusses some of its common and possible future usage patterns, with particular attention to those factors that have aided its success in practice.Comment: 12 pages, 3 figures. Accepted for Virtual Observatory special issue of Astronomy and Computin

    A scale-model room as a practical teaching experiment

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    A practical experiment is described which was used to help university students increase their understanding of the effect of construction methods and window design on passive solar heating and electrical heating. A number of one tenth scale model rooms were constructed by students and sited out-of-doors in the late autumn. The models were fabricated to mimic available commercial construction techniques with careful consideration being given to window size and placement for solar access. Each model had a thermostatically controlled electric heating element. The temperatures and electricity use of the models were recorded using data-loggers over a two week period. The performances of the models based on energy consumption and internal temperature were compared with each other and with predictions based upon thermal mass and R-values. Examples of questions used by students to facilitate this process are included. The effect of scaling on thermal properties was analysed using Buckingham&rsquo;s p-theorem.<br /

    Empirical pricing kernels obtained from the UK index options market

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    Empirical pricing kernels for the UK equity market are derived as the ratio between risk-neutral densities, inferred from FTSE 100 index options, and historical real-world densities, estimated from time series of the index. The kernels thus obtained are almost compatible with a risk averse representative agent, unlike similar estimates for the US market

    String universality in ten dimensions

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    We show that the N=1{\cal N}=1 supergravity theories in ten dimensions with gauge groups U(1)496U(1)^{496} and E8×U(1)248E_8 \times U(1)^{248} are not consistent quantum theories. Cancellation of anomalies cannot be made compatible with supersymmetry and abelian gauge invariance. Thus, in ten dimensions all supersymmetric theories of gravity without known inconsistencies are realized in string theory.Comment: 7 pages, 1 figure, LaTeX. v2: typos corrected on version appearing in PR

    Effect of geometry on hydrodynamic film thickness

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    The influence of geometry on the isothermal hydrodynamic film separating two rigid solids was investigated. Pressure-viscosity effects were not considered. The minimum film thickness is derived for fully flooded conjunctions by using the Reynolds conditions. It was found that the minimum film thickness had the same speed, viscosity, and load dependence as Kapitza's classical solution. However, the incorporation of Reynolds boundary conditions resulted in an additional geometry effect. Solutions using the parabolic film approximation are compared with those using the exact expression for the film in the analysis. Contour plots are shown that indicate in detail the pressure developed between the solids

    Condensation cyclization reactions of electron deficient aromatics. 4: Tricyclic nitropropene nitronates from the reaction of phloroglucinol and cycloalkanones with sym-trinitrobenzene

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    Interesting similarities have been shown between the reactions of sym-trinitrobenzene with cycloalkanones, and with phloroglucinol. Previously unsuspected common intermediates have been shown to intervene. The structurally similar products in each case are tricyclic nitropropene nitronates. Protonation of these yields the corresponding nitronic acids in certain instances
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