21,707 research outputs found

    Landau Collision Integral Solver with Adaptive Mesh Refinement on Emerging Architectures

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    The Landau collision integral is an accurate model for the small-angle dominated Coulomb collisions in fusion plasmas. We investigate a high order accurate, fully conservative, finite element discretization of the nonlinear multi-species Landau integral with adaptive mesh refinement using the PETSc library (www.mcs.anl.gov/petsc). We develop algorithms and techniques to efficiently utilize emerging architectures with an approach that minimizes memory usage and movement and is suitable for vector processing. The Landau collision integral is vectorized with Intel AVX-512 intrinsics and the solver sustains as much as 22% of the theoretical peak flop rate of the Second Generation Intel Xeon Phi, Knights Landing, processor

    ALCOHOLS AS COMPONENTS OF TRANSPORTATION FUELS

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    Alcohols have the potential to revolutionize energy fuel supply and use, particularly in transportation. This worldwide potential is based on (a) the variety of widely available raw materials from which alcohols can be made (coal, natural gas, petroleum, and biomass), (b) the improved and demon­ strated technology for alcohol manufacture and use, and (c) the favorable combustion characteristics of alcohols, namely clean burning with high octane performance

    Building data analytics capability to increase information processing capacity: The case of a professional service firm

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    Supply chain literature has emphasised the importance of data analytics capability in driving supply chain outcomes. Additionally, along with knowledge and professional judgement, providing data-driven analyses has become a critical component of professional service operations. However, there remains little understanding of how organisations build data analytics capability to reduce supply network uncertainty. A single case study of a professional service firm revealed analytics capability to be a combination of three capabilities, each with its distinct micro-foundations. We argue that the development of analytics capability requires the interaction of individual abilities and knowledge-bases with social and technical interorganisational processes and structures

    The importance of DNA methylation in prostate cancer development.

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    After briefly reviewing the nature of DNA methylation, its general role in cancer and the tools available to interrogate it, we consider the literature surrounding DNA methylation as relating to prostate cancer. Specific consideration is given to recurrent alterations. A list of frequently reported genes is synthesized from 17 studies that have reported on methylation changes in malignant prostate tissue, and we chart the timing of those changes in the diseases history through amalgamation of several previously published data sets. We also review associations with genetic alterations and hormone signalling, before the practicalities of investigating prostate cancer methylation using cell lines are assessed. We conclude by outlining the interplay between DNA methylation and prostate cancer metabolism and their regulation by androgen receptor, with a specific discussion of the mitochondria and their associations with DNA methylation.CEM is funded by an ERC grant. IGM is supported in Oslo by funding from the Norwegian Research Council, Helse Sor-Ost and the University of Oslo through the Centre for Molecular Medicine (Norway), which is a part of the Nordic EMBL (European Molecular Biology Laboratory) partnership. IGM holds a visiting scientist position with Cancer Research UK through the Cambridge Research Institute and a Senior Honorary Visiting Research Fellowship with Cambridge University through the Department of Oncology. IGM is supported in Belfast by the Belfast-Manchester Movember Centre of Excellence (CE013_2-004), funded in partnership with Prostate Cancer UK. AGL is supported by a Cancer Research UK programme grant (C14303/A20406) to Simon TavarĂŠ and by the European Commission through the Horizon 2020 project SOUND (Grant Agreement no. 633974). CEM and AGL acknowledge the support of the University of Cambridge, Cancer Research UK and Hutchison Whampoa Limited.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jsbmb.2016.04.00

    Global adaptation in networks of selfish components: emergent associative memory at the system scale

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    In some circumstances complex adaptive systems composed of numerous self-interested agents can self-organise into structures that enhance global adaptation, efficiency or function. However, the general conditions for such an outcome are poorly understood and present a fundamental open question for domains as varied as ecology, sociology, economics, organismic biology and technological infrastructure design. In contrast, sufficient conditions for artificial neural networks to form structures that perform collective computational processes such as associative memory/recall, classification, generalisation and optimisation, are well-understood. Such global functions within a single agent or organism are not wholly surprising since the mechanisms (e.g. Hebbian learning) that create these neural organisations may be selected for this purpose, but agents in a multi-agent system have no obvious reason to adhere to such a structuring protocol or produce such global behaviours when acting from individual self-interest. However, Hebbian learning is actually a very simple and fully-distributed habituation or positive feedback principle. Here we show that when self-interested agents can modify how they are affected by other agents (e.g. when they can influence which other agents they interact with) then, in adapting these inter-agent relationships to maximise their own utility, they will necessarily alter them in a manner homologous with Hebbian learning. Multi-agent systems with adaptable relationships will thereby exhibit the same system-level behaviours as neural networks under Hebbian learning. For example, improved global efficiency in multi-agent systems can be explained by the inherent ability of associative memory to generalise by idealising stored patterns and/or creating new combinations of sub-patterns. Thus distributed multi-agent systems can spontaneously exhibit adaptive global behaviours in the same sense, and by the same mechanism, as the organisational principles familiar in connectionist models of organismic learning

    Three-coloring statistical model with domain wall boundary conditions. I. Functional equations

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    In 1970 Baxter considered the statistical three-coloring lattice model for the case of toroidal boundary conditions. He used the Bethe ansatz and found the partition function of the model in the thermodynamic limit. We consider the same model but use other boundary conditions for which one can prove that the partition function satisfies some functional equations similar to the functional equations satisfied by the partition function of the six-vertex model for a special value of the crossing parameter.Comment: 16 pages, notations changed for consistency with the next part, appendix adde

    Combining Multi-Criteria Decision Making (MCDM) Methods with Building Information Modelling (BIM): A Review

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    Integrating building information to support decision-making has been a key challenge in the Architecture, Engineering, and Construction (AEC) industry. The synergy of Building Information Modelling (BIM) and Multi-Criteria Decision Making (MCDM) is expected to improve information integration and decision-making. The aim of this paper is to identify strategies to improve the synergy between MCDM and BIM. From the earliest literature (2009) to the present, this study examines 45 articles combining MCDM with BIM. We find that the five major application domains are sustainability, retrofit, supplier selection, safety, and constructability. Five established strategies for improving the synergy between MCDM and BIM were discussed and can be used as a benchmark for evaluating the application of decision techniques in practice. This study points out gaps of combining MCDM and BIM in the current literature. It also sheds new light into combining MCDM with BIM for practitioners, as to promote integrated decision-making

    Reactivity difference between protolytic forms of some macrocyclic chromium(III) complexes in ligand substitution and electron transfer processes

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    The review provides insight into the mechanism of ligand substitution and electron transfer (from chromium( III) to iron(III)) by comparison of the reactivity of some tetraazamacrocyclic chromium(III) complexes in the conjugate acid-base forms. Use of two geometrical isomers made possible to estimate the influence of geometry and protolytic reactions in trans and cis position towards the leaving group on the rate enhancement. Studies on the reaction rates in different media demonstrated the role played by outer sphere interactions in a monodentate ligand substitution
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