4,729 research outputs found

    Integrated Project Teams: The MoD's New Hot Potato?

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    Since the announcement of Smart Procurement, much has been written on the potential benefits that IPTs will hopefully bring. It is supposed that they will improve the interface with industry, create a better understanding of requirements and establish an environment where industry is motivated to perform and so reduce cost, risk and time into service while improving product quality. The formation of a team should provide continuity, consistency, flexibility and ~ increased performance due to the integration of a wide-range of functional activities and decision-making, as well as increased motivation. These may well be gallant objectives, but how achievable are they? What obstacles does the MoD face in the implementation of the IPTs? Have they grasped a 'hot potato'

    Photon Emission from Ultrarelativistic Plasmas

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    The emission rate of photons from a hot, weakly coupled ultrarelativistic plasma is analyzed. Leading-log results, reflecting the sensitivity of the emission rate to scattering events with momentum transfers from gTgT to TT, have previously been obtained. But a complete leading-order treatment requires including collinearly enhanced, inelastic processes such as bremsstrahlung. These inelastic processes receive O(1) modifications from multiple scattering during the photon emission process, which limits the coherence length of the emitted radiation (the Landau-Pomeranchuk-Migdal effect). We perform a diagrammatic analysis to identify, and sum, all leading-order contributions. We find that the leading-order photon emission rate is not sensitive to non-perturbative g2Tg^2 T scale dynamics. We derive an integral equation for the photon emission rate which is very similar to the result of Migdal in his original discussion of the LPM effect. The accurate solution of this integral equation for specific theories of interest will be reported in a companion paper.Comment: 50 pages, 20 figures. Added references and minor rewordings: published versio

    Estimating χtop\chi_\mathrm{top} Lattice Artifacts from Flowed SU(2) Calorons

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    Lattice computations of the high-temperature topological susceptibility of QCD receive lattice-spacing corrections and suffer from systematics arising from the type and depth of gradient flow. We study the lattice spacing corrections to χtop\chi_\mathrm{top} semi-analytically by exploring the behavior of discretized Harrington-Shepard calorons under the action of different forms of gradient flow. From our study we conclude that Nτ=6N_\tau = 6 is definitely too small of a time extent to study the theory at temperatures of order 4 Tc4~T_\mathrm{c} and we explore how the amount of gradient flow influences the continuum extrapolation.Comment: 10 pages, 8 figures (published version

    Is sea-basing a viable method of providing logistic support to the UK amphibious force?

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    Maritime power has traditionally been a central part of the UK’s defence planning and is well suited to supporting a wide range of military operations. The littoral area has always created problems for naval planners as most landings historically have had to endure a tactical separation of the naval and land components, and hence an artificial seam between the Navy and the Marines. With the end of the Cold War, amphibious operations are going to be more difficult to conduct than in the past, and amphibious forces are going to have to adopt manoeuvre warfare capabilities in order to successfully complete their missions. It is very likely that amphibious forces will have to conduct operations against a numerically superior enemy, who is on his own terrain, and be surrounded by a neutral, if not hostile populace. As such, the concept of Operational Manoeuvre From The Sea (OMFTS) whereby the sea is used as a manoeuvre space, and command and control is fast enough to cope with large amounts of information, but at the same time allow subordinates maximum flexibility to use their initiative, is increasingly attractive. It will be important not only for the combat elements to be able to use this new concept, but the Combat Service Support (CSS) elements as well

    Implications for the U.S. of Anglo-French Defense Cooperation

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    The paper analyzes, from a predominantly UK perspective, the implications for the U.S. of the November 2, 2010, Anglo-French Defence Cooperation Treaty. The current pressures on British and French defence budgets were the primary driving force behind this cooperative effort. London and Paris have made steps toward improving joint efforts in a number of areas, with defence acquisition and industrial cooperation being prominent. In the UK, there appears to be strong political support at the highest levels, which has permeated to lower levels in the bureaucracy, while the UK defence industry appears to be cautiously optimistic about future business opportunities. The impact of enhanced Anglo-French cooperation on the U.S. would appear to be largely favourable for Washington. Rather than providing a basis for weakened UK attention to the U.S., as some fear, the efforts by London and Paris will potentially generate greater national military capability from scarce resources and could serve as a vehicle for broader European efforts to enhance their defence capabilities. While multinational European military development projects are viewed with scepticism in the UK, the Anglo-French arrangement could strengthen the prospects for bilateral projects in which other European states may elect to participate
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