12,472 research outputs found

    Airport-Noise Levels and Annoyance Model (ALAMO) user's guide

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    A guide for the use of the Airport-Noise Level and Annoyance MOdel (ALAMO) at the Langley Research Center computer complex is provided. This document is divided into 5 primary sections, the introduction, the purpose of the model, and an in-depth description of the following subsystems: baseline, noise reduction simulation and track analysis. For each subsystem, the user is provided with a description of architecture, an explanation of subsystem use, sample results, and a case runner's check list. It is assumed that the user is familiar with the operations at the Langley Research Center (LaRC) computer complex, the Network Operating System (NOS 1.4) and CYBER Control Language. Incorporated within the ALAMO model is a census database system called SITE II

    Euler number of Instanton Moduli space and Seiberg-Witten invariants

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    We show that a partition function of topological twisted N=4 Yang-Mills theory is given by Seiberg-Witten invariants on a Riemannian four manifolds under the condition that the sum of Euler number and signature of the four manifolds vanish. The partition function is the sum of Euler number of instanton moduli space when it is possible to apply the vanishing theorem. And we get a relation of Euler number labeled by the instanton number kk with Seiberg-Witten invariants, too. All calculation in this paper is done without assuming duality.Comment: LaTeX, 34 page

    Safer technology, safer users: The UK as a world-leader in Safety Tech

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    Explaining anomalous responses to treatment in the Intensive Care Unit

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    The Intensive Care Unit (ICU) provides treatment to critically ill patients. When a patient does not respond as expected to such treatment it can be challenging for clinicians, especially junior clinicians, as they may not have the relevant experience to understand the patient’s anomalous response. Datasets for 10 patients from Glasgow Royal Infirmary’s ICU have been made available to us. We asked several ICU clinicians to review these datasets and to suggest sequences which include anomalous or unusual reactions to treatment. Further, we then asked two ICU clinicians if they agreed with their colleagues’ assessments, and if they did to provide possible explanations for these anomalous sequences. Subsequently we have developed a system which is able to replicate the clinicians’ explanations based on the knowledge contained in its several ontologies; further the system can suggest additional explanations which will be evaluated by the senior consultant

    Stability of Affine G-varieties and Irreducibility in Reductive Groups

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    Let GG be a reductive affine algebraic group, and let XX be an affine algebraic GG-variety. We establish a (poly)stability criterion for points xXx\in X in terms of intrinsically defined closed subgroups HxH_{x} of GG, and relate it with the numerical criterion of Mumford, and with Richardson and Bate-Martin-R\"ohrle criteria, in the case X=GNX=G^{N}. Our criterion builds on a close analogue of a theorem of Mundet and Schmitt on polystability and allows the generalization to the algebraic group setting of results of Johnson-Millson and Sikora about complex representation varieties of finitely presented groups. By well established results, it also provides a restatement of the non-abelian Hodge theorem in terms of stability notions.Comment: 29 pages. To appear in Int. J. Math. Note: this version 4 is identical with version 2 (version 3 is empty

    The ADHM Construction of Instantons on Noncommutative Spaces

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    We present an account of the ADHM construction of instantons on Euclidean space-time R4\mathbb{R}^4 from the point of view of noncommutative geometry. We recall the main ingredients of the classical construction in a coordinate algebra format, which we then deform using a cocycle twisting procedure to obtain a method for constructing families of instantons on noncommutative space-time, parameterised by solutions to an appropriate set of ADHM equations. We illustrate the noncommutative construction in two special cases: the Moyal-Groenewold plane R4\mathbb{R}^4_\hbar and the Connes-Landi plane Rθ4\mathbb{R}^4_\theta.Comment: Latex, 40 page

    State space c-reductions for concurrent systems in rewriting logic

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    We present c-reductions, a state space reduction technique. The rough idea is to exploit some equivalence relation on states (possibly capturing system regularities) that preserves behavioral properties, and explore the induced quotient system. This is done by means of a canonizer function, which maps each state into a (non necessarily unique) canonical representative of its equivalence class. The approach exploits the expressiveness of rewriting logic and its realization in Maude to enjoy several advantages over similar approaches: exibility and simplicity in the definition of the reductions (supporting not only traditional symmetry reductions, but also name reuse and name abstraction); reasoning support for checking and proving correctness of the reductions; and automatization of the reduction infrastructure via Maude's meta-programming features. The approach has been validated over a set of representative case studies, exhibiting comparable results with respect to other tools

    N=2 Topological Yang-Mills Theory on Compact K\"{a}hler Surfaces

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    We study a topological Yang-Mills theory with N=2N=2 fermionic symmetry. Our formalism is a field theoretical interpretation of the Donaldson polynomial invariants on compact K\"{a}hler surfaces. We also study an analogous theory on compact oriented Riemann surfaces and briefly discuss a possible application of the Witten's non-Abelian localization formula to the problems in the case of compact K\"{a}hler surfaces.Comment: ESENAT-93-01 & YUMS-93-10, 34pages: [Final Version] to appear in Comm. Math. Phy

    Formal specification of QoS properties

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    We describe the specification of communication services, with special emphasis being placed on the use of the Temporal Logic of Actions (TLA) to describe the behaviours involved. We show how, startingfrom Message Sequence Charts, this temporal logic may be used to describe The Joint Viewing and Tele Operating Service (JVTOS) and its associated functions; and so lead on to the specification of QoS parameters. We discuss the approach that was taken to determine the exact nature of the Quality of Service parameters, and how the method may be used to extend the specification, and probe further aspects of the services and protocols involved
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