2,806 research outputs found

    Uniformly high order accurate essentially non-oscillatory schemes 3

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    In this paper (a third in a series) the construction and the analysis of essentially non-oscillatory shock capturing methods for the approximation of hyperbolic conservation laws are presented. Also presented is a hierarchy of high order accurate schemes which generalizes Godunov's scheme and its second order accurate MUSCL extension to arbitrary order of accuracy. The design involves an essentially non-oscillatory piecewise polynomial reconstruction of the solution from its cell averages, time evolution through an approximate solution of the resulting initial value problem, and averaging of this approximate solution over each cell. The reconstruction algorithm is derived from a new interpolation technique that when applied to piecewise smooth data gives high-order accuracy whenever the function is smooth but avoids a Gibbs phenomenon at discontinuities. Unlike standard finite difference methods this procedure uses an adaptive stencil of grid points and consequently the resulting schemes are highly nonlinear

    Study on Performance of Different Fodder Crops under Low Cost Green House Hydroponic Fodder Production System

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    Hydroponics play most significant role in augmenting fodder shortage and helps for dairy production efficiently. A study was conducted to assess the performance and suitability of different crops under low cost green house hydroponic fodder production unit at SHE&CS Krishi Vigyan Kendra, Yagantipalle. Four varieties of cereals grains and four verities of Pulses were tested. One kilogram grain each of the variety was soaked for 12 hours in water for sprouting in air tight condition for 36 hours. The sprouted seed was spread in trays of size 2.5 ft X 1.5ft and kept in the Hydroponic Unit. Automatic sprinkling of water was managed by cyclic timer. Chemical fertilizer was not used. Data on sprouted seed weight and weight of biomass after 5 days was recorded using electronic weighing balance. The high biomass yield after 5days in cereals was recorded in Bajra followed by sorghum, Barley and Maize. Among pulses Pillipesara yielded highest weight followed by Cowpea, Lucerne and Horse gram. Highest plant height among cereals was recorded in Barley and cowpea in pulses. The difference among all the varieties in respect of biomass yield and plant height was found to be significant. Negative correlation was found between plant height and biomass yield

    Analysis of Automotive Cyber-Attacks on Highways using Partial Differential Equation Models

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    This is the author accepted manuscript.This paper considers scenarios wherein a group of malicious vehicles on a highway perform a cooperative attack with the motive of creating undesirable wave effects among other vehicles on the highway. The two species of vehicles - malicious vehicles and normal vehicles, and their associated interaction effects, are modeled using Partial Differential Equations (PDEs). The malicious vehicles, which may be arbitrarily distributed on the highway, perform a sequence of velocity changes with the objective of making the density/velocity profile on the highway, track a reference profile. This reference profile (chosen by the malicious vehicles) has the property that once generated, it spontaneously evolves into a shock wave that propagates along the highway. Analytical expressions governing the velocity inputs of the malicious vehicles with which they can generate such waves are determined, for perfect as well as imperfect information scenarios. Simulation results are presented to validate the theoryThe first two authors would like to acknowledge support from the National Science Foundation. This material is based upon work supported by the National Science Foundation under Grant IIS-1351677

    Applying semantic web technologies to knowledge sharing in aerospace engineering

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    This paper details an integrated methodology to optimise Knowledge reuse and sharing, illustrated with a use case in the aeronautics domain. It uses Ontologies as a central modelling strategy for the Capture of Knowledge from legacy docu-ments via automated means, or directly in systems interfacing with Knowledge workers, via user-defined, web-based forms. The domain ontologies used for Knowledge Capture also guide the retrieval of the Knowledge extracted from the data using a Semantic Search System that provides support for multiple modalities during search. This approach has been applied and evaluated successfully within the aerospace domain, and is currently being extended for use in other domains on an increasingly large scale

    Motor symptoms in Parkinson's disease: A unified framework

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    Parkinson’s disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (akinesia and bradykinesia, tremor and rigidity), PD patients show additional motor deficits, including: gait disturbance, impaired handwriting, grip force and speech deficits, among others. Some of these motor symptoms (e.g., deficits of gait, speech, and handwriting) have similar clinical profiles, neural substrates, and respond similarly to dopaminergic medication and deep brain stimulation (DBS). Here, we provide an extensive review of the clinical characteristics and neural substrates of each of these motor symptoms, to highlight precisely how PD and its medical and surgical treatments impact motor symptoms. In conclusion, we offer a unified framework for understanding the range of motor symptoms in PD. We argue that various motor symptoms in PD reflect dysfunction of neural structures responsible for action selection, motor sequencing, and coordination and execution of movement

    Consistent Anisotropic Repulsions for Simple Molecules

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    We extract atom-atom potentials from the effective spherical potentials that suc cessfully model Hugoniot experiments on molecular fluids, e.g., O2O_2 and N2N_2. In the case of O2O_2 the resulting potentials compare very well with the atom-atom potentials used in studies of solid-state propertie s, while for N2N_2 they are considerably softer at short distances. Ground state (T=0K) and room temperatu re calculations performed with the new NNN-N potential resolve the previous discrepancy between experimental and theoretical results.Comment: RevTeX, 5 figure
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