22,838 research outputs found

    The Great Hurricane and Tidal Wave of 1938: Scenes of the Disaster in Rhode Island’s East Bay

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    In September of 1983 a hurricane swept across New England. It was one of the most destructive storms to ever strike the region, causing damage in New York, Rhode Island, Connecticut, Massachusetts, New Hampshire, Vermont, and Maine

    The Proposed Federal Securities Code: Time to Recognize That Financial Information Becomes Stale

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    This note addresses the Federal Securities Code ( Code ), developed by the American Law Institute ( ALI ). It specifically focuses on the underlying policy of continuous disclosure implemented by the Code, which requires companies to register once and then continuously disclose to the securities marketplace important developments on their financial position. This note poses a question: At what point does financial information become stale? It focuses on the nature of stale financial information by reviewing the treatment of staleness in common law fraud and bankruptcy cases. It then analyzes the approach taken with regard to stale financial information in existing securities law. Finally, it concludes by proposing that an objective definition of staleness should be incorporated into the Code, placing reasonable limits on the liability created under the Code\u27s continuous disclosure requirements

    Fire and rescue service community safety initiatives: measuring impact

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    Purpose - The purpose of this paper is to discuss methods of capturing the impact of fire and rescue service (FRS) community safety work which directly aims to reduce the occurrence of specific incidents. Design/methodology/approach - The impact assessment method described focuses on addressing one of the major problems with regards to attributing outcomes to FRS community safety work; the influence of external factors. This paper looked to assess the incident trends within a case study UK FRS within the context of the following external data sets: first, incident trends within other UK FRSs; second, demographic trends; and third, incident data from other public services. Findings - There were instances, either across the whole region served by the case study FRS, or within specific districts, where evidence suggested a strong likelihood of the community safety work of the case study FRS contributing towards an observed reduction in incidents. These findings were established through filtering the impact of widespread external factors, which could impact upon incident figures. Research limitations/implications - The utility of this impact assessment relies upon FRS consistently recording the specific aims and focus of individual community safety activity, so that any positive outcomes can be attributed to a particular group of community safety initiatives. Originality/value - This paper discusses how an evaluation process, to deter mine the likelihood of community safety impacting upon incident numbers, can be practically applied to a FRS

    Remarks on explicit strong ellipticity conditions for anisotropic or pre-stressed incompressible solids

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    We present a set of explicit conditions, involving the components of the elastic stiffness tensor, which are necessary and sufficient to ensure the strong ellipticity of an orthorhombic incompressible medium. The derivation is based on the procedure developed by Zee & Sternberg (Arch. Rat. Mech. Anal., 83, 53-90 (1983)) and, consequently, is also applicable to the case of the homogeneously pre-stressed incompressible isotropic solids. This allows us to reformulate the results by Zee & Sternberg in terms of components of the incremental stiffness tensor. In addition, the resulting conditions are specialized to higher symmetry classes and compared with strong ellipticity conditions for plane strain, commonly used in the literature.The first author’s work and the second author’s visit to Brunel University were partly supported by Brunel University’s ‘BRIEF’ award scheme

    Embedded Eigenvalues and the Nonlinear Schrodinger Equation

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    A common challenge to proving asymptotic stability of solitary waves is understanding the spectrum of the operator associated with the linearized flow. The existence of eigenvalues can inhibit the dispersive estimates key to proving stability. Following the work of Marzuola & Simpson, we prove the absence of embedded eigenvalues for a collection of nonlinear Schrodinger equations, including some one and three dimensional supercritical equations, and the three dimensional cubic-quintic equation. Our results also rule out nonzero eigenvalues within the spectral gap and, in 3D, endpoint resonances. The proof is computer assisted as it depends on the sign of certain inner products which do not readily admit analytic representations. Our source code is available for verification at http://www.math.toronto.edu/simpson/files/spec_prop_asad_simpson_code.zip.Comment: 29 pages, 27 figures: fixed a typo in an equation from the previous version, and added two equations to clarif

    Managing urban socio-technical change? Comparing energy technology controversies in three European contexts

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    A {\em local graph partitioning algorithm} finds a set of vertices with small conductance (i.e. a sparse cut) by adaptively exploring part of a large graph GG, starting from a specified vertex. For the algorithm to be local, its complexity must be bounded in terms of the size of the set that it outputs, with at most a weak dependence on the number nn of vertices in GG. Previous local partitioning algorithms find sparse cuts using random walks and personalized PageRank. In this paper, we introduce a randomized local partitioning algorithm that finds a sparse cut by simulating the {\em volume-biased evolving set process}, which is a Markov chain on sets of vertices. We prove that for any set of vertices AA that has conductance at most ϕ\phi, for at least half of the starting vertices in AA our algorithm will output (with probability at least half), a set of conductance O(ϕ1/2log⁥1/2n)O(\phi^{1/2} \log^{1/2} n). We prove that for a given run of the algorithm, the expected ratio between its computational complexity and the volume of the set that it outputs is O(ϕ−1/2polylog(n))O(\phi^{-1/2} polylog(n)). In comparison, the best previous local partitioning algorithm, due to Andersen, Chung, and Lang, has the same approximation guarantee, but a larger ratio of O(ϕ−1polylog(n))O(\phi^{-1} polylog(n)) between the complexity and output volume. Using our local partitioning algorithm as a subroutine, we construct a fast algorithm for finding balanced cuts. Given a fixed value of ϕ\phi, the resulting algorithm has complexity O((m+nϕ−1/2)polylog(n))O((m+n\phi^{-1/2}) polylog(n)) and returns a cut with conductance O(ϕ1/2log⁥1/2n)O(\phi^{1/2} \log^{1/2} n) and volume at least vϕ/2v_{\phi}/2, where vϕv_{\phi} is the largest volume of any set with conductance at most ϕ\phi.Comment: 20 pages, no figure

    Numerical comparison of pipe-column-separation models

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    Results comparing six column-separation numerical models for simulating localized vapor cavities and distributed vaporous cavitation in pipelines are presented. The discrete vapor-cavity model (DVCM) is shown to be quite sensitive to selected input parameters. For short pipeline systems, the maximum pressure rise following column separation can vary markedly for small changes in wave speed, friction factor, diameter, initial velocity, length of pipe, or pipe slope. Of the six numerical models, three perform consistently over a broad number of reaches. One of them, the discrete gas-cavity model, is recommended for general use as it is least sensitive to input parameters or to the selected discretization of the pipeline. Three models provide inconsistent estimates of the maximum pressure rise as the number of reaches is increased; however, these models do give consistent results provided the ratio of maximum cavity size to reach volume is kept below 10%.Angus R. Simpson and Anton Bergan
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