975 research outputs found

    Security policy refinement using data integration: a position paper.

    No full text
    In spite of the wide adoption of policy-based approaches for security management, and many existing treatments of policy verification and analysis, relatively little attention has been paid to policy refinement: the problem of deriving lower-level, runnable policies from higher-level policies, policy goals, and specifications. In this paper we present our initial ideas on this task, using and adapting concepts from data integration. We take a view of policies as governing the performance of an action on a target by a subject, possibly with certain conditions. Transformation rules are applied to these components of a policy in a structured way, in order to translate the policy into more refined terms; the transformation rules we use are similar to those of global-as-view database schema mappings, or to extensions thereof. We illustrate our ideas with an example. Copyright 2009 ACM

    SOFTWARE SOLUTIONS FOR MEASURING AND FORECASTING THE CASH GENERATING UNIT FLOWS RELATED TO INTANGIBLE ASSETS

    Get PDF
    In light of the difficulties encountered in assessing the value of the CGU (Cash Generating Unit) and of the cash flows associated with goodwill or other intangible assets of a company and after performing the impairment test as provided by the IAS 36-Intangibile Asset and the forecasts related to it, the aim of this paper is to identify and suggest software instruments that would assist in the measurement and forecasting of these elements. The employment of the SPSS and the NeuroShell programmes in analyzing and forecasting the changes in CGU and CGU flows has helped compare the results and the ensuing error margins, thus giving the business entity the possibility to select the best software option, depending on certain variables identified on a micro or a macroeconomic level that may affect the depreciation or the increases in value of the underlying assets for CGU or CGU flows

    The Tethered Moon

    Get PDF
    Cosmic collisions between terrestrial planets resemble somewhat the life cycle of the phoenix: worlds collide, are consumed in flame, and after the debris has cleared, shiny new worlds emerge aglow with possibilities. And glow they do, for they are molten. How brightly they glow, and for how long, is determined by their atmospheres and their moons. A reasonable initial condition on Earth after the Moon-forming impact is that it begins as a hot global magma ocean. We therefore begin our study with the mantle as a liquid ocean with a surface temperature on the order of 3000-4000 K at a time some 100-1000 years after the impact, by which point we can hope that early transients have settled down

    Observations and modeling of H_2 fluorescence with partial frequency redistribution in giant planet atmospheres

    Full text link
    Partial frequency redistribution (PRD), describing the formation of the line profile, has negligible observational effects for optical depths smaller than ~10^3, at the resolving power of most current instruments. However, when the spectral resolution is sufficiently high, PRD modeling becomes essential in interpreting the line shapes and determining the total line fluxes. We demonstrate the effects of PRD on the H_2 line profiles observed at high spectral resolution by the Far-Ultraviolet Spectroscopic Explorer (FUSE) in the atmospheres of Jupiter and Saturn. In these spectra, the asymmetric shapes of the lines in the Lyman (v"- 6) progression pumped by the solar Ly-beta are explained by coherent scattering of the photons in the line wings. We introduce a simple computational approximation to mitigate the numerical difficulties of radiative transfer with PRD, and show that it reproduces the exact radiative transfer solution to better than 10%. The lines predicted by our radiative transfer model with PRD, including the H_2 density and temperature distribution as a function of height in the atmosphere, are in agreement with the line profiles observed by FUSE. We discuss the observational consequences of PRD, and show that this computational method also allows us to include PRD in modeling the continuum pumped H_2 fluorescence, treating about 4000 lines simultaneously.Comment: 17 pages, accepted for publication in Ap

    Data Supply Chain (DSC): development and validation of a measurement instrument

    Get PDF
    The volume and availability of data produced and affordably stored has become an important new resource for building organizational competitive advantage. Reflecting this, and expanding the concept of the supply chain, we propose the Data Supply Chain (DSC) as a novel concept to aid investigations into how the interconnected data characteristics relate to and impact organizational performance. Initially, we define the concept and develop a research agenda on DSC coupling theoretical background of strategy and operations literature. Along with the conceptualization, we develop a set of propositions and make suggestions for future research including testing and validating the model fit

    erbB-2 antisense oligonucleotides inhibit the proliferation of breast carcinoma cells with erbB-2 oncogene amplification.

    Get PDF
    Amplification and overexpression of the erbB-2 oncogene is an unfavourable prognostic marker in human breast cancer and occurs in approximately 25% of breast carcinomas. We used erbB-2 antisense oligonucleotides to inhibit the proliferation of human breast cancer cell lines. erbB-2 antisense oligonucleotides (20 microM) inhibited the growth and DNA synthesis of breast cancer cell lines with an amplified erbB-2 gene by up to 60%. Control complementary sense oligonucleotides did not inhibit cellular proliferation at the same concentration but showed inhibitory effects at higher concentrations. There was no specific effect of erbB-2 antisense oligonucleotides on breast cancer cell lines that had no amplification of erbB-2. erbB-2 antisense oligonucleotides reduced erbB-2 protein levels, measured by immunohistochemistry, in a dose-dependent manner. erbB-2 sense oligonucleotides did not decrease the levels of erbB-2 protein. These data indicate that erbB-2 antisense oligonucleotides induce a specific inhibition of erbB-2 protein expression and that erbB-2 gene overexpression is important for the proliferation of the breast cancer cells that have been selected for erbB-2 amplification

    Retrieval of atmospheric properties of cloudy L dwarfs

    Get PDF
    Ā© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.We present the first results from applying the spectral inversion technique in the cloudy L dwarf regime. Our new framework provides a flexible approach to modelling cloud opacity which can be built incrementally as the data requires, and improves upon previous retrieval experiments in the brown dwarf regime by allowing for scattering in two stream radiative transfer. Our first application of the tool to two mid-L dwarfs is able to reproduce their near-infrared spectra far more closely than grid models. Our retrieved thermal, chemical, and cloud profiles allow us to estimate Teff=1796āˆ’25+23T_{\rm eff} = 1796^{+23}_{-25} K and logā”g=5.21āˆ’0.08+0.05\log g = 5.21^{+0.05}_{-0.08} for 2MASS J05002100+0330501 and for 2MASSW J2224438-015852 we find Teff=1723āˆ’19+18T_{\rm eff} = 1723^{+18}_{-19} K and logā”g=5.31āˆ’0.08+0.04\log g = 5.31^{+0.04}_{-0.08}, in close agreement with previous empirical estimates. Our best model for both objects includes an optically thick cloud deck which passes Ļ„cloudā‰„1\tau_{cloud} \geq 1 (looking down) at a pressure of around 5 bar. The temperature at this pressure is too high for silicate species to condense, and we argue that corundum and/or iron clouds are responsible for this cloud opacity. Our retrieved profiles are cooler at depth, and warmer at altitude than the forward grid models that we compare, and we argue that some form of heating mechanism may be at work in the upper atmospheres of these L dwarfs. We also identify anomalously high CO abundance in both targets, which does not correlate with the warmth of our upper atmospheres or our choice of cloud model, and find similarly anomalous alkali abundance for one of our targets. These anomalies may reflect unrecognised shortcomings in our retrieval model, or inaccuracies in our gas phase opacities.Peer reviewedFinal Accepted Versio
    • ā€¦
    corecore